Crystalline forms of neurotrophin mimetic compounds and their salts

ABSTRACT

The present invention includes crystalline forms of 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide and crystalline forms of salts and/or solvates of 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide. Furthermore, the present invention provides compositions comprising the crystalline forms and therapeutic use of the crystalline forms.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a continuation of U.S. application Ser. No.13/509,470, entitled “CRYSTALLINE FORMS OF NEUROTROPHIN MIMETICCOMPOUNDS AND THEIR SALTS,” filed Aug. 29, 2012 which is a NationalStage Entry of PCT/US2010/056537, filed on Nov. 12, 2010 and entitled“CRYSTALLINE FORMS OF NEUROTROPHIN MIMETIC COMPOUNDS AND THEIR SALTS”which claims the benefit of U.S. Provisional Application No. 61/260,671,filed on Nov. 12, 2009 and entitled “THERAPEUTIC COMPOUNDS USEFUL FORTREATING P75 RELATED CONDITIONS INCLUDING NEURODEGENERATIVE DISORDERS”;U.S. Provisional Application No. 61/294,279, filed on Jan. 12, 2010 andentitled “CRYSTALLINE FORMS OF NEUROTROPHIN MIMETIC COMPOUNDS AND THEIRSALTS”; and U.S. Provisional Application No. 61/350,797, filed on Jun.2, 2010 and entitled “CRYSTALLINE FORMS OF NEUROTROPHIN MIMETICCOMPOUNDS AND THEIR SALTS”; the contents of which are herebyincorporated by reference in their entireties for all purposes.

FIELD OF THE INVENTION

The present invention relates to crystalline forms of neurotrophinmimetic compounds and crystalline forms of the salts and/or solvates ofneurotrophin mimetic compounds, processes of preparing the crystallineforms, and methods of using them.

BACKGROUND OF THE INVENTION

Neurotrophins are polypeptides that play a role in the development,function, and/or survival of certain cells, including neurons,oligodendrocytes, Schwann cells, hair follicle cells, and other cells.The death or dysfunction of neurons and other cell types has beendirectly implicated in a number of neurodegenerative disorders. It hasbeen suggested that alterations in neurotrophin localization, expressionlevels of neurotrophins, and/or expression levels of the receptors thatbind neurotrophins are therefore linked to neuronal degeneration.Degeneration occurs in the neurodegenerative disorders Alzheimer's,Parkinson's and ALS, among others. Degeneration of oligodendrocytes canoccur in central nervous system injury, multiple sclerosis, and otherpathological states.

A variety of neurotrophins have been identified, including Nerve GrowthFactor (NGF), Neurotrophin-3 (NT-3), Neurotrophin-4/5 (NT-4/5),Neurotrophin 6 (NT-6) and Brain Derived Neurotrophic Factor (BDNF).Neurotrophins are found in both precursor form, known aspro-neurotrophins, and in mature form. The mature forms are proteins ofabout 120 amino acids in length that exist in physiological states asstable, non-covalent approximately 25 kDa homodimers. Each neurotrophinmonomer includes three solvent-exposed β-hairpin loops, referred to asloops 1, 2, and 4 that exhibit relatively high degrees of amino acidconservation across the neurotrophin family.

Mature neurotrophins bind preferentially to the receptors Trk andp75^(NTR) (p75 neurotrophin receptor, also called the Low Affinity NerveGrowth Factor Receptor or LNGFR) while pro-neurotrophins, which containan N-terminal domain proteolytically removed in mature forms, interactprincipally with p75^(NTR) and through their N-terminal domains, withthe sorting receptor sortilin (Fahnestock, M., et al. (2001) Mol CellNeurosci 18, 210-220; Harrington, A. W. et al. (2004) Proc Natl Acad SciUSA 101, 6226-6230; Nykiaer. A. et al., (2004) Nature 427, 843-848).p75^(NTR) interacts with Trks and modulates Trk signaling, but is alsoindependently coupled to several signaling systems, includingpro-survival signals, IRAK/TRAF6/NF.kappa.B, PI3/AKT, and pro-apoptoticsignals, NRAGE/JNK (Mamidipudi, V., et al. (2002) J Biol Chem 277,28010-28018; Roux, P. P., et al. (2001) J Biol Chem 276, 23097-23104;Salehi, A. H., et al. (2000) Neuron 27, 279-288).

When administered for therapeutic use, neurotrophins exhibit suboptimalpharmacological properties, including poor stability with low serum halflives, likely poor oral bioavailability, and restricted central nervoussystem penetration (Podulso, J. F., Curran, G. L. (1996) Brain Res MolBrain Res 36, 280-286; Saltzman, W. M., et al (1999) Pharm Res 16,232-240; Partridge, W. M. (2002) Adv Exp Med Bio 513, 397-430).Additionally, the highly pleiotropic effects of neurotrophins achievedthrough action of the dual receptor signaling network increases thechances of adverse effects.

It has been suggested that the unliganded form of p75^(NTR) isproapoptotic, and that homodimerization induced by neurotrophin bindingeliminates the effect (Wang, J. J., et al (2000) J Neurosci Res 60,587-593), consistent with studies showing no effects on survival ofmonomeric p75^(NTR) ligands, including monovalent Fabs (Maliartchouk,S., et al (2000) J Biol Chem 275, 9946-9956) and monomeric cyclicpeptides (Longo, F. M., (1997) J Neurosci Res 48, 1-17), while relatedbivalent forms in each study promote cell survival. However, thesemonomeric ligands may not engage the receptor in the same way as thenatural ligands. Though active NGF is a homodimers containing 2potential p75^(NTR) binding sites, recent structural evidence suggeststhat it engages only one p75^(NTR) molecule, disallowing the binding ofanother (He, X. L., (2004) Science 304, 870-875).

Unfortunately, technical and ethical considerations have thus farhampered the development of therapeutic agents based upon neurotrophins.For example, it is technically difficult to produce sufficientquantities of pure neurotrophins using recombinant DNA techniques.Additionally, although it is possible to utilize human fetal cells toproduce neurotrophins, the ethical ramifications raised by the use ofsuch cells (typically obtained from an aborted fetus) have all butprevented the utilization of this approach. Accordingly, there is anunmet need in the art for the development of small molecule agents withfavorable drug-like features based upon neurotrophins, i.e.,neurotrophin mimetics, that are capable of targeting specificneurotrophin receptors for use in the treatment of disorders ordiseases. U.S. Patent Application Publication Nos. 2006/024072 and2007/0060526 describe certain neurotrophin mimetics, and the contents ofthese two publications are herein incorporated by reference in theirentirety for all purposes.

Those skilled in the pharmaceutical arts understand that crystallizationof an active pharmaceutical ingredient offers the best method forcontrolling important physiochemical qualities, such as stability,solubility, bioavailability, particle size, bulk density, flowproperties, polymorphic content, and other properties. Thus, there is aneed for crystalline forms of neurotrophin mimetics and processes toproduce such forms. These crystalline forms should be suitable forpharmaceutical use.

SUMMARY OF THE INVENTION

In one embodiment, the present invention provides a crystalline form ofa compound or a salt and/or solvate thereof, wherein the compound is2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide. In one embodiment,the present invention provides a crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide. In anotherembodiment, the present invention provides a crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monosulfate. Inanother embodiment, the present invention provides a crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide disulfate. In anotherembodiment, the present invention provides a crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide digluconate. Inanother embodiment, the present invention provides a crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dimesylate. Inanother embodiment, the present invention provides a crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide ditosylate. Inanother embodiment, the present invention provides a crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dinapsylate. Inanother embodiment, the present invention provides a crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monoedisylate. Inanother embodiment, the present invention provides a crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monooxalate.

In one embodiment, the present invention provides a compositioncomprising the crystalline form of the present invention.

In one embodiment, the present invention provides a method of treating adisorder involving degeneration or dysfunction of cells expressing p75comprising administering to a patient in need of such treatment acomposition comprising the crystalline form of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph of a x-ray powder diffraction (XRD) pattern of theamorphous di-HCl salt of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide.

FIG. 2 is an overlay of DSC and TGA thermograms of the amorphous di-HClsalt of (2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide.

FIGS. 3A and 3B are DVS plots of the amorphous di-HCl salt of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide.

FIG. 4 is a H-NMR, i.e., proton NMR, spectrum of the amorphous di-HClsalt of (2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide.

FIG. 5 is a graph of a x-ray powder diffraction (XRD) pattern of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide (free base).

FIG. 6 is an overlay of DSC and TGA thermograms of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide (free base).

FIG. 7 is a H-NMR spectrum of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide (free base).

FIGS. 8A and 8B are Raman spectrum of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide (free base).

FIGS. 9A and 9B are DVS plots of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide (free base).

FIG. 10 is a graph of a x-ray powder diffraction (XRD) pattern of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monosulfate.

FIG. 11 is a DSC thermogram of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monosulfate.

FIGS. 12A and 12B are Raman spectrum of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monosulfate.

FIG. 13 is a graph of a x-ray powder diffraction (XRD) pattern of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide disulfate.

FIG. 14 is a DSC thermogram of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide disulfate.

FIG. 15 is a TGA thermogram of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide disulfate.

FIGS. 16A and 16B are DVS plots of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide disulfate.

FIG. 17 is a H-NMR spectrum of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide disulfate.

FIGS. 18A and 18B are Raman spectrum of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide disulfate.

FIG. 19 is a graph of a x-ray powder diffraction (XRD) pattern of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide digluconate.

FIG. 20 is a DSC thermogram of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide digluconate.

FIG. 21 is a TGA thermogram of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide digluconate.

FIGS. 22A and 22B are DVS plots of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide digluconate.

FIG. 23 is a H-NMR spectrum of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide digluconate.

FIGS. 24A and 24B are Raman spectrum of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide digluconate.

FIG. 25 is a graph of a x-ray powder diffraction (XRD) pattern of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dimesylate.

FIG. 26A is a DSC thermogram of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dimesylate.FIG. 26B is a TGA thermogram of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dimesylate.

FIGS. 27A and 27B are DVS plots of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dimesylate.

FIG. 28 is a H-NMR spectrum of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dimesylate.

FIG. 29 is Raman spectrum of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dimesylate.

FIG. 30 is a graph of a x-ray powder diffraction (XRD) pattern of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide ditosylate.

FIG. 31A is a DSC thermogram of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide ditosylate.FIG. 31B is a TGA thermogram of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide ditosylate.

FIGS. 32A and 32B are DVS plots of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide ditosylate.

FIG. 33 is a H-NMR spectrum of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide ditosylate.

FIG. 34 is Raman spectrum of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide ditosylate.

FIG. 35 is a graph of a x-ray powder diffraction (XRD) pattern of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dinapsylate.

FIG. 36A is a DSC thermogram of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dinapsylate.FIG. 36B is a TGA thermogram of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dinapsylate.

FIGS. 37A and 37B are DVS plots of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dinapsylate.

FIG. 38 is a H-NMR spectrum of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dinapsylate.

FIG. 39 is Raman spectrum of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dinapsylate.

FIG. 40 is a graph of a x-ray powder diffraction (XRD) pattern of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamidemonoedisylate.

FIG. 41A is a DSC thermogram of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamidemonoedisylate. FIG. 41B is a TGA thermogram of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamidemonoedisylate.

FIGS. 42A and 42B are DVS plots of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamidemonoedisylate.

FIG. 43 is a H-NMR spectrum of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamidemonoedisylate.

FIG. 44 is Raman spectrum of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamidemonoedisylate.

FIG. 45 is a graph of a x-ray powder diffraction (XRD) pattern of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monooxalate.

FIG. 46A is a DSC thermogram of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monooxalate.FIG. 46B is a TGA thermogram of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monooxalate.

FIGS. 47A and 47B are DVS plots of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monooxalate.

FIG. 48 is a H-NMR spectrum of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monooxalate.

FIG. 49 is Raman spectrum of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monooxalate.

FIG. 50 is a graph of H-NMR spectrum of stability study of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide free base.

FIG. 51 is a graph of H-NMR spectrum of stability study of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide disulfate.

FIG. 52 is a graph of H-NMR spectrum of stability study of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide ditosylate.

FIG. 53 is a graph of H-NMR spectrum of stability study of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dinapsylate.

FIG. 54 is a graph of H-NMR spectrum of stability study of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamidemonoedisylate.

DETAILED DESCRIPTIONS OF THE INVENTION

In patients with disorders related to degeneration or dysfunction ofcells expressing p75, such as neurodegenerative disorders, alterationsin neurotrophin localization, expression levels of neurotrophins,expression levels of the receptors that bind neurotrophins, and/orreceptor signaling and functional outcomes can occur. Accordingly, byproviding patients suffering from such disorders with a correspondingneurotrophic factor or mimetic thereof that modulates p75^(NTR) functionor proNGF/NGF binding to prevent cellular degeneration or dysfunction,such neural degeneration can be alleviated or prevented.

The present invention relates to crystalline forms of neurotrophinmimetic compounds as well as crystalline forms of salts and/or solvatesof neurotrophin mimetic compounds. These crystalline materials can beformulated into pharmaceutical compositions and used for treatingdisorders involving degeneration or dysfunction of cells expressing p75.

Definitions

It is to be understood that the terminology used herein is for thepurpose of describing particular embodiments only and is not intended tobe limiting.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood to one of ordinary skill inthe art to which the present application belongs. Although any methodsand materials similar or equivalent to those described herein can beused in the practice or testing of the present application,representative methods and materials are herein described.

Following long-standing patent law convention, the terms “a”, “an”, and“the” refer to “one or more” when used in this application, includingthe claims. Thus, for example, reference to “a carrier” includesmixtures of one or more carriers, two or more carriers, and the like.

Unless otherwise indicated, all numbers expressing quantities ofingredients, reaction conditions, and so forth used in the specificationand claims are to be understood as being modified in all instances bythe term “about”. Accordingly, unless indicated to the contrary, thenumerical parameters set forth in the present specification and attachedclaims are approximations that can vary depending upon the desiredproperties sought to be obtained by the present application. Generallythe term “about”, as used herein when referring to a measurable valuesuch as an amount of weight, time, dose, etc. is meant to encompass inone example variations of ±20% or ±10%, in another example ±5%, inanother example ±1%, and in yet another example ±0.1% from the specifiedamount, as such variations are appropriate to perform the disclosedmethod.

The term “compound(s) of the present invention”, “present compound(s)”,or “2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide” refers to thecrystalline forms of 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamidedescribed throughout the application including a crystalline form of anysingle enantiomer of 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide,a mixture of any two enantiomers of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide, a mixture of anythree enantiomers of 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide,and a mixture of any four enantiomers of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide.

Polymorphism can be characterized as the ability of a compound tocrystallize into different crystal forms, while maintaining the samechemical formula. A crystalline polymorph of a given drug substance ischemically identical to any other crystalline polymorph of that drugsubstance in containing the same atoms bonded to one another in the sameway, but differs in its crystal forms, which can affect one or morephysical properties, such as stability, solubility, melting point, bulkdensity, flow properties, bioavailability, etc.

The term “composition” denotes one or more substance in a physical form,such as solid, liquid, gas, or a mixture thereof. One example ofcomposition is a pharmaceutical composition, i.e., a composition relatedto, prepared for, or used in medical treatment.

The term “carboxylic acid” refers to an organic acid characterized byone or more carboxyl groups, such as acetic acid and oxalic acid.“Sulfonic acid” refers to an organic acid with the general formula ofR—(S(O)₂—OH)_(n), wherein R is an organic moiety and n is an integerabove zero, such as 1, 2, and 3. The term “polyhydroxy acid” refers to acarboxylic acid containing two or more hydroxyl groups. Examples ofpolyhydroxy acid include, but are not limited to, lactobionic acid,gluconic acid, and galactose.

“Neurotrophin mimetic compound” denotes an organic compound thatresembles the biological function or activity of neurotrophin.

As used herein, “pharmaceutically acceptable” means suitable for use incontact with the tissues of humans and animals without undue toxicity,irritation, allergic response, and the like, commensurate with areasonable benefit/risk ratio, and effective for their intended usewithin the scope of sound medical judgment.

“Salts” include derivatives of an active agent, wherein the active agentis modified by making acid or base addition salts thereof. Preferably,the salts are pharmaceutically acceptable salts. Such salts include, butare not limited to, pharmaceutically acceptable acid addition salts,pharmaceutically acceptable base addition salts, pharmaceuticallyacceptable metal salts, ammonium and alkylated ammonium salts. Acidaddition salts include salts of inorganic acids as well as organicacids. Representative examples of suitable inorganic acids includehydrochloric, hydrobromic, hydroiodic, phosphoric, sulfuric, nitricacids and the like. Representative examples of suitable organic acidsinclude formic, acetic, trichloroacetic, trifluoroacetic, propionic,benzoic, cinnamic, citric, fumaric, glycolic, lactic, maleic, malic,malonic, mandelic, oxalic, picric, pyruvic, salicylic, succinic,methanesulfonic, ethanesulfonic, tartaric, ascorbic, pamoic,bismethylene salicylic, ethanedisulfonic, gluconic, citraconic,aspartic, stearic, palmitic, EDTA, glycolic, p-aminobenzoic, glutamic,benzenesulfonic, p-toluenesulfonic acids, sulphates, nitrates,phosphates, perchlorates, borates, acetates, benzoates,hydroxynaphthoates, glycerophosphates, ketoglutarates and the like. Baseaddition salts include but are not limited to, ethylenediamine,N-methyl-glucamine, lysine, arginine, ornithine, choline,N,N′-dibenzylethylenediamine, chloroprocaine, diethanolamine, procaine,N-benzylphenethylamine, diethylamine, piperazine,tris-(hydroxymethyl)-aminomethane, tetramethylammonium hydroxide,triethylamine, dibenzylamine, ephenamine, dehydroabietylamine,N-ethylpiperidine, benzylamine, tetramethylammonium, tetraethylammonium,methylamine, dimethylamine, trimethylamine, ethylamine, basic aminoacids, e. g., lysine and arginine dicyclohexylamine and the like.Examples of metal salts include lithium, sodium, potassium, magnesiumsalts and the like. Examples of ammonium and alkylated ammonium saltsinclude ammonium, methylammonium, dimethylammonium, trimethylammonium,ethylammonium, hydroxyethylammonium, diethylammonium, butylammonium,tetramethylammonium salts and the like. Examples of organic basesinclude lysine, arginine, guanidine, diethanolamine, choline and thelike. Standard methods for the preparation of pharmaceuticallyacceptable salts and their formulations are well known in the art, andare disclosed in various references, including for example, “Remington:The Science and Practice of Pharmacy”, A. Gennaro, ed., 20th edition,Lippincott, Williams & Wilkins, Philadelphia, Pa.

As used herein, “solvate” means a complex formed by solvation (thecombination of solvent molecules with molecules or ions of the activeagent of the present invention), or an aggregate that consists of asolute ion or molecule (the active agent of the present invention) withone or more solvent molecules. In the present invention, the preferredsolvate is hydrate. Examples of hydrate include, but are not limited to,hemihydrate, monohydrate, dihydrate, trihydrate, hexahydrate, etc. Itshould be understood by one of ordinary skill in the art that thepharmaceutically acceptable salt of the present compound may also existin a solvate form. The solvate is typically formed via hydration whichis either part of the preparation of the present compound or throughnatural absorption of moisture by the anhydrous compound of the presentinvention. Solvates including hydrates may be consisting instoichiometric ratios, for example, with two, three, four salt moleculesper solvate or per hydrate molecule. Another possibility, for example,that two salt molecules are stoichiometric related to three, five, sevensolvent or hydrate molecules. Solvents used for crystallization, such asalcohols, especially methanol and ethanol; aldehydes; ketones,especially acetone; esters, e.g. ethyl acetate; may be embedded in thecrystal grating. Preferred are pharmaceutically acceptable solvents.

The term “substantially similar” as used herein means an analyticalspectrum, such as XRD pattern, Raman spectroscopy, and etc., whichresembles the reference spectrum to a great degree in both the peaklocations and their intensity.

The terms “excipient”, “carrier”, and “vehicle” are usedinterexchangeably throughout this application and denote a substancewith which a compound of the present invention is administered.

“Therapeutically effective amount” means the amount of a crystallineform that, when administered to a patient for treating a disease orother undesirable medical condition, is sufficient to have a beneficialeffect with respect to that disease or condition. The therapeuticallyeffective amount will vary depending on the crystalline form, thedisease or condition and its severity, and the age, weight, etc. of thepatient to be treated. Determining the therapeutically effective amountof a given crystalline form is within the ordinary skill of the art andrequires no more than routine experimentation.

As used herein, the phrase “a disorder involving degeneration ordysfunction of cells expressing p75” includes, but is not limited to,disorders related to upregulation of p75. Such disorders includeneurodegenerative disorders, as well as conditions involvingdegeneration of p75^(NTR)-expressing cells, such as hair loss. Withinthe nervous system, the p75 receptor is expressed by various cell typesincluding neurons, oligodendrocytes, astrocytes. Compounds targeting p75receptors expressed by neurons can be used to prevent loss of function,degeneration and/or death of neurons in a number of nervous systemdisorders including (but not limited to) Alzheimer's disease,Parkinson's disease, Huntington's disease, stroke, traumatic braininjury, spinal cord injury, epilepsy, multiple sclerosis, amyotrophiclateral sclerosis, neuropathies, myopathies and various forms of retinaldegeneration. In each of these disorders, neurons expressing p75 areaffected.

Crystalline Materials

In one embodiment, the present invention provides a crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide (free base). Inanother embodiment, the present invention provides a crystalline form ofa salt and/or solvate of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide. In one embodiment,the salt is a sulfuric acid addition salt. In one embodiment, the saltis a sulfonic acid addition salt. In one embodiment, the salt is acarboxylic acid addition salt. In one embodiment, the salt is apolyhydroxy acid addition salt. Examples of the crystalline saltinclude, but are not limited to, monosulfate, disulfate, digluconate,dimesylate, ditosylate, dinapsylate, monoedisylate, and monooxalate. Thenaphthalenesulfonic acid, which forms dinapsylate salt with2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide, can be1-naphthalenesulfonic acid, 2-naphthalenesulfonic acid, or3-naphthalenesulfonic acid. In one embodiment, the naphthalenesulfonicacid is 2-naphthalenesulfonic acid. The compound of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide is selected from thegroup consisting of:(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide;(2R,3R)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide;(2R,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide;(2S,3R)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide; and amixture thereof. Scheme A shows the chemical structures of the presentcompounds.

In one embodiment, the crystalline forms are characterized by theinterlattice plane intervals determined by a X-ray powder diffractionpattern (XRDP). The spectrum of XRDP is typically represented by adiagram plotting the intensity of the peaks versus the location of thepeaks, i.e., diffraction angle 20 (two-theta) in degrees. Theintensities are often given in parenthesis with the followingabbreviations: very strong=vst; strong=st; medium=m; weak=w; and veryweak=vw. The characteristic peaks of a given XRDP can be selectedaccording to the peak locations and their relative intensity toconveniently distinguish this crystalline structure from others.

Those skilled in the art recognize that the measurements of the XRDPpeak locations and/or intensity for a given crystalline form of the samecompound will vary within a margin of error. The values of degree 2θallow appropriate error margins. Typically, the error margins arerepresented by “±”. For example, the degree 2θ of about “8.716±0.3”denotes a range from about 8.716+0.3, i.e., about 9.016, to about8.716−0.3, i.e., about 8.416. Depending on the sample preparationtechniques, the calibration techniques applied to the instruments, humanoperational variation, and etc, those skilled in the art recognize thatthe appropriate error of margins for a XRDP can be ±0.5; ±0.4; ±0.3;±0.2; ±0.1; ±0.05; or less.

Additional details of the methods and equipments used for the XRDPanalysis are described in the Examples section.

In one embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide exhibits an XRDPcomprising peaks at about 8.716; 15.438; and 19.198 degrees two-thetawith the margin of error of about ±0.5; about ±0.4; about ±0.3; about±0.2; about ±0.1; about ±0.05; or less. In another embodiment, the XRDPof the crystalline form further comprises peaks at about 20.912 and20.599 degrees two-theta with the margin of error of about ±0.5; about±0.4; about ±0.3; about ±0.2; about ±0.1; about ±0.05; or less. In yetanother embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide exhibits an XRDPcomprising peaks shown in the table below:

TABLE 1 XRDP Table of 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide. Angle d value 2-Theta ° AngstromIntensity % 8.716 10.13693  53.2 (vst) 15.438 5.73486 100.0 (vst) 16.554 5.35074  7.0 (w) 17.514 5.05977 15.3 (m) 18.358 4.82894  8.6 (w)19.198 4.61948  30.4 (vst) 19.773 4.48646 17.8 (m) 20.126 4.40854  9.0(w) 20.599 4.30831 20.8 (st)  20.912 4.24452 27.7 (st)  22.391 3.96741 5.6 (w) 23.200 3.83088 11.5 (m) 23.867 3.72529  7.4 (w) 24.390 3.6466111.4 (m) 25.709 3.46243 14.3 (m) 26.387 3.37497 13.0 (m) 29.629 3.01264 4.9 (vw) 30.822 2.89872  4.8 (vw) 31.270 2.85819  4.9 (vw)In one specific embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide exhibits an XRDP thatis substantially similar to FIG. 5. In another specific embodiment, thecompound 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide as describedin the above embodiments is(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide.

In one embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monosulfate exhibitsan XRDP comprising peaks at about 25.306 and about 27.027 degreestwo-theta with the margin of error of about ±0.5; about ±0.4; about±0.3; about ±0.2; about ±0.1; about ±0.05; or less. In anotherembodiment, the XRDP of the crystalline form further comprises a peak atabout 17.449 degrees two-theta with the margin of error of about ±0.5;about ±0.4; about ±0.3; about ±0.2; about ±0.1; about ±0.05; or less. Inyet another embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monosulfate exhibitsan XRDP comprising peaks shown in the table below:

TABLE 2 XRDP Table of 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monosulfate. Angle d value 2-Theta ° Angstrom Intensity %17.449 5.07811 43.3 (vst) 25.306 3.51657 100.0 (vst)  27.027 3.2963472.7 (vst)In one specific embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monosulfate exhibitsan XRDP that is substantially similar to FIG. 10. In another specificembodiment, the compound2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monosulfate asdescribed in the above embodiments is(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monosulfate.

In one embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide disulfate exhibits anXRDP comprising peaks at about 21.784; 22.468; and 19.277 degreestwo-theta with the margin of error of about ±0.5; about ±0.4; about±0.3; about ±0.2; about ±0.1; about ±0.05; or less. In anotherembodiment, the XRDP of the crystalline form further comprises peaks atabout 24.618 and 15.499 degrees two-theta with the margin of error ofabout ±0.5; about ±0.4; about ±0.3; about ±0.2; about ±0.1; about ±0.05;or less. In yet another embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide disulfate exhibits anXRDP comprising peaks shown in the table below:

TABLE 3 XRDP Table of 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide disulfate. Angle d value 2-Theta ° AngstromIntensity % 8.572 10.30642  7.9 (w) 10.390 8.50740  5.5 (w) 15.4995.71227 16.6 (m) 18.550 4.77929  9.7 (w) 19.277 4.60050  32.6 (vst)20.208 4.39062 19.9 (m) 21.784 4.07644 100.0 (vst)  22.468 3.95387  44.7(vst) 24.618 3.61327 23.5 (st)  26.472 3.36417 12.1 (m) 27.178 3.2783712.3 (m) 28.107 3.17216  9.6 (w)In one specific embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide disulfate exhibits anXRDP that is substantially similar to FIG. 13. In another specificembodiment, the compound2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide disulfate asdescribed in the above embodiments is(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide disulfate.

In one embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide digluconate exhibitsan XRDP comprising peaks at about 19.447; 24.377; and 22.637 degreestwo-theta with the margin of error of about ±0.5; about ±0.4; about±0.3; about ±0.2; about ±0.1; about ±0.05; or less. In anotherembodiment, the XRDP of the crystalline form further comprises peaks atabout 15.730 and 7.768 degrees two-theta with the margin of error ofabout ±0.5; about ±0.4; about ±0.3; about ±0.2; about ±0.1; about ±0.05;or less. In yet another embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide digluconate exhibitsan XRDP comprising peaks shown in the table below:

TABLE 4 XRDP Table of 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide digluconate. Angle d value 2-Theta ° Angstrom Intensity %7.768 11.37097 60.9 (vst) 9.071 9.74106 23.1 (st)  15.730 5.62923 88.8(vst) 19.447 4.56067 100.0 (vst)  21.198 4.18776 57.3 (vst) 22.6373.92466 93.3 (vst) 24.377 3.64838 99.1 (vst) 25.981 3.42667 59.4 (vst)28.856 3.09148 25.8 (st)  31.182 2.86600 45.3 (vst)In one specific embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide digluconate exhibitsan XRDP that is substantially similar to FIG. 19. In another specificembodiment, the compound2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide digluconate asdescribed in the above embodiments is(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide digluconate.

In one embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dimesylate exhibitsan XRDP comprising peaks at about 8.499, 21.162, and 22.292 degreestwo-theta with the margin of error of about ±0.5; about ±0.4; about±0.3; about ±0.2; about ±0.1; about ±0.05; or less. In anotherembodiment, the XRDP of the crystalline form further comprises peaks atabout 9.421, 16.543, and 18.912 degrees two-theta with the margin oferror of about ±0.5; about ±0.4; about ±0.3; about ±0.2; about ±0.1;about ±0.05; or less. In yet another embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dimesylate exhibitsan XRDP comprising peaks shown in the table below:

TABLE 5 XRDP Table of 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dimesylate. Angle d value Intensity 2-Theta Angstrom CountIntensity % 8.499 10.395 37.3 100 9.421 9.37978 27.3 87.7 12.837 6.8903612.3 39.5 13.412 6.59644 8.87 28.5 15.812 5.60013 15.3 49.1 16.5435.35436 21.4 68.8 17.093 5.18306 14 45 18.912 4.68856 19.8 63.6 21.1624.19476 29.3 93.9 22.292 3.98469 31.2 100 24.884 3.5752 11.5 36.9 25.7673.45468 14.2 45.5 29.585 3.01697 7.6 24.4In one specific embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dimesylate exhibitsan XRDP that is substantially similar to FIG. 25. In another specificembodiment, the compound2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dimesylate asdescribed in the above embodiments is(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dimesylate.

In one embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide ditosylate exhibitsan XRDP comprising peaks at about 6.021 and 18.078 degrees two-thetawith the margin of error of about ±0.5; about ±0.4; about ±0.3; about±0.2; about ±0.1; about ±0.05; or less. In another embodiment, the XRDPof the crystalline form further comprises peaks at about 17.557, 20.475,and 11.029 degrees two-theta with the margin of error of about ±0.5;about ±0.4; about ±0.3; about ±0.2; about ±0.1; about ±0.05; or less. Inyet another embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide ditosylate exhibitsan XRDP comprising peaks shown in the table below:

TABLE 6 XRDP Table of 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide ditosylate. Angle d value Intensity 2-Theta ° Angstrom CountIntensity % 6.021 14.66728 96.1 100 11.029 8.01566 23.2 24.2 12.766.9319 11.9 12.4 14.281 6.1967 10.4 10.9 15.738 5.62628 12.3 12.8 17.5575.04708 32.3 33.6 18.078 4.90303 40.9 42.6 20.475 4.33393 34.2 35.624.332 3.65501 13.7 14.2 25.504 3.48965 13.8 14.4In one specific embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide ditosylate exhibitsan XRDP that is substantially similar to FIG. 30. In another specificembodiment, the compound2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide ditosylate asdescribed in the above embodiments is(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide ditosylate.

In one embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dinapsylate exhibitsan XRDP comprising peaks at about 5.943, 15.872, and 18.515 degreestwo-theta with the margin of error of about ±0.5; about ±0.4; about±0.3; about ±0.2; about ±0.1; about ±0.05; or less. In anotherembodiment, the XRDP of the crystalline form further comprises peaks atabout 22.046 degree two-theta with the margin of error of about ±0.5;about ±0.4; about ±0.3; about ±0.2; about ±0.1; about ±0.05; or less. Inyet another embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dinapsylate exhibitsan XRDP comprising peaks shown in the table below:

TABLE 7 XRDP Table of 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dinapsylate. Angle d value Intensity 2-Theta ° AngstromCount Intensity % 5.943 14.85943 56.2 100 8.018 11.0176 5.25 9.3 11.0058.03299 12.2 21.8 14.985 5.90739 8.89 15.8 15.872 5.57894 29.5 52.518.515 4.78809 28.9 51.5 19.454 4.5592 12.1 21.5 22.046 4.02857 18.833.5 24.35 3.65239 14 24.9 27.8 3.20642 8.75 15.6 29.279 3.04776 9.9117.6In one specific embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dinapsylate exhibitsan XRDP that is substantially similar to FIG. 35. In another specificembodiment, the compound2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dinapsylate asdescribed in the above embodiments is(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dinapsylate.

In one embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monoedisylateexhibits an XRDP comprising peaks at about 7.447 and 20.406 degreestwo-theta with the margin of error of about ±0.5; about ±0.4; about±0.3; about ±0.2; about ±0.1; about ±0.05; or less. In anotherembodiment, the XRDP of the crystalline form further comprises peaks atabout 23.443 and 22.244 degrees two-theta with the margin of error ofabout ±0.5; about ±0.4; about ±0.3; about ±0.2; about ±0.1; about ±0.05;or less. In yet another embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monoedisylateexhibits an XRDP comprising peaks shown in the table below:

TABLE 8 XRDP Table of 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monoedisylate. Angle d value Intensity 2-Theta ° AngstromCount Intensity % 7.447 11.86098 42.9 100 12.023 7.3552 7.88 18.4 13.9716.33368 5.58 13 14.812 5.9759 14.7 34.3 15.933 5.55777 10.5 24.5 17.6245.02816 10.3 24 19.273 4.60157 11 25.5 20.406 4.34846 40.5 94.5 22.2443.99321 23.5 54.8 23.443 3.79165 28.8 67.2 24.161 3.68047 14.4 33.627.481 3.2429 8.72 20.3 29.684 3.0071 6.98 16.3In one specific embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monoedisylateexhibits an XRDP that is substantially similar to FIG. 40. In anotherspecific embodiment, the compound2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monoedisylate asdescribed in the above embodiments is(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamidemonoedisylate.

In one embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monooxalate exhibitsan XRDP comprising peaks at about 7.260 and 19.671 degrees two-thetawith the margin of error of about ±0.5; about ±0.4; about ±0.3; about±0.2; about ±0.1; about ±0.05; or less. In another embodiment, the XRDPof the crystalline form further comprises peaks at about 18.917 and16.024 degrees two-theta with the margin of error of about ±0.5; about±0.4; about ±0.3; about ±0.2; about ±0.1; about ±0.05; or less. In yetanother embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monooxalate exhibitsan XRDP comprising peaks shown in the table below:

TABLE 9 XRDP Table of 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monooxalate. Angle d value Intensity 2-Theta ° AngstromCount Intensity % 7.26 12.16562 33.4 100 10.872 8.13099 14.5 43.3 12.5947.0227 8.34 24.9 13.844 6.39151 12.9 38.5 14.436 6.13074 10.5 31.316.024 5.52652 21.4 64.1 18.116 4.89273 15.3 45.6 18.917 4.6874 26.579.2 19.671 4.50923 30.3 90.6 20.782 4.27066 15.9 47.7 22.52 3.9448316.7 50 25.221 3.52813 8.81 26.3In one specific embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monooxalate exhibitsan XRDP that is substantially similar to FIG. 45. In another specificembodiment, the compound2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monooxalate asdescribed in the above embodiments is(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monooxalate.

In one embodiment, the crystalline forms are characterized by Ramanspectroscopy. The Raman spectrum is typically represented by a diagramplotting the Raman intensity of the peaks versus the Raman shift of thepeaks. The “peaks” of Raman spectroscopy are also known as “absorptionbands”. The intensities are often given in parenthesis with thefollowing abbreviations: strong=st; medium=m; and weak=w. Thecharacteristic peaks of a given Raman spectrum can be selected accordingto the peak locations and their relative intensity to convenientlydistinguish this crystalline structure from others.

Those skilled in the art recognize that the measurements of the Ramanpeak shifts and/or intensity for a given crystalline form of the samecompound will vary within a margin of error. The values of peak shift,expressed in reciprocal wave numbers (cm⁻¹), allow appropriate errormargins. Typically, the error margins are represented by “±”. Forexample, the Raman shift of about “1310±10” denotes a range from about1310+10, i.e., about 1320, to about 1310−10, i.e., about 1300. Dependingon the sample preparation techniques, the calibration techniques appliedto the instruments, human operational variations, and etc, those skilledin the art recognize that the appropriate error of margins for a Ramanshift can be ±12; ±10; ±8; ±5; ±3; ±1; or less.

Additional details of the methods and equipments used for the Ramanspectroscopy analysis are described in the Examples section.

In one embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide exhibits an Ramanspectrum comprising peaks at about 2964 (s); about 2873 (s); and about1451 (s) cm⁻¹ with the error of margin of about ±12; about ±10; about±8; about ±5; about ±3; about ±1; or less. In another embodiment, theRaman spectrum further comprises peaks at about 1310 (m) and about 805(m) cm⁻¹ with the error of margin of about ±12; about ±10; about ±8;about ±5; about ±3; about ±1; or less. In one specific embodiment, thecrystalline form of 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamideexhibits a Raman spectrum that is substantially similar to FIGS. 8A and8B. In another specific embodiment, the compound2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide as described in theabove embodiments is(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide.

In one embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monosulfate exhibitsan Raman spectrum comprising peaks at about 2964 (s); about 2880 (s);and about 972 (s) cm⁻¹ with the error of margin of about ±12; about ±10;about ±8; about ±5; about ±3; about ±1; or less. In another embodiment,the Raman spectrum further comprises peaks at about 1448 (m) and about1310 (m) cm⁻¹ with the error of margin of about ±12; about ±10; about±8; about ±5; about ±3; about ±1; or less. In one specific embodiment,the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monosulfate exhibitsa Raman spectrum that is substantially similar to FIGS. 12A and 12B.

In another specific embodiment, the compound2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monosulfate asdescribed in the above embodiments is(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monosulfate.

In one embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide disulfate exhibits anRaman spectrum comprising peaks at about 2980 (s); about 2943 (s); about2889 (s); and about 1033 (s) cm⁻¹ with the error of margin of about ±12;about ±10; about ±8; about ±5; about ±3; about ±1; or less. In anotherembodiment, the Raman spectrum further comprises peaks at about 975 (m)and about 851 (m) cm⁻¹ with the error of margin of about ±12; about ±10;about ±8; about ±5; about ±3; about ±1; or less. In one specificembodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide disulfate exhibits aRaman spectrum that is substantially similar to FIGS. 18A and 18B. Inanother specific embodiment, the compound2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide disulfate asdescribed in the above embodiments is(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide disulfate.

In one embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide digluconate exhibitsan Raman spectrum comprising peaks at about 2957 (s); about 2928 (s);and about 910 (s) cm⁻¹ with the error of margin of about ±12; about ±10;about ±8; about ±5; about ±3; about ±1; or less. In another embodiment,the Raman spectrum further comprises peaks at about 1450 (m); about 1139(m); and about 883 (m) cm⁻¹ with the error of margin of about ±12; about±10; about ±8; about ±5; about ±3; about ±1; or less. In one specificembodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide digluconate exhibitsa Raman spectrum that is substantially similar to FIGS. 24A and 24B. Inanother specific embodiment, the compound2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide digluconate asdescribed in the above embodiments is(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide digluconate.

In one embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dimesylate exhibitsan Raman spectrum comprising peaks at about 2935 (s); about 1040 (s);and about 778 (s) cm⁻¹ with the error of margin of about ±12; about ±10;about ±8; about ±5; about ±3; about ±1; or less. In another embodiment,the Raman spectrum further comprises peaks at about 1444 (m) and about557 (m) cm⁻¹ with the error of margin of about ±12; about ±10; about ±8;about ±5; about ±3; about ±1; or less. In one specific embodiment, thecrystalline form of 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamidedimesylate exhibits a Raman spectrum that is substantially similar toFIG. 29. In another specific embodiment, the compound2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dimesylate asdescribed in the above embodiments is(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dimesylate.

In one embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide ditosylate exhibitsan Raman spectrum comprising peaks at about 2980 (s); about 1123 (s);and about 800 (s) cm⁻¹ with the error of margin of about ±12; about ±10;about ±8; about ±5; about ±3; about ±1; or less. In another embodiment,the Raman spectrum further comprises peaks at about 2922 (m), about 1599(m), and about 637 (m) cm⁻¹ with the error of margin of about ±12; about±10; about ±8; about ±5; about ±3; about ±1; or less. In one specificembodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide ditosylate exhibits aRaman spectrum that is substantially similar to FIG. 34. In anotherspecific embodiment, the compound2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide ditosylate asdescribed in the above embodiments is(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide ditosylate.

In one embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dinapsylate exhibitsan Raman spectrum comprising peaks at about 3053 (w); about 1380 (s);and about 766 (s) cm⁻¹ with the error of margin of about ±12; about ±10;about ±8; about ±5; about ±3; about ±1; or less. In another embodiment,the Raman spectrum further comprises peaks at about 2974 (w) and about514 (m) cm⁻¹ with the error of margin of about ±12; about ±10; about ±8;about ±5; about ±3; about ±1; or less. In one specific embodiment, thecrystalline form of 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamidedinapsylate exhibits a Raman spectrum that is substantially similar toFIG. 39. In another specific embodiment, the compound2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dinapsylate asdescribed in the above embodiments is(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dinapsylate.

In one embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monoedisylateexhibits an Raman spectrum comprising peaks at about 2954 (s); about1058 (s); and about 825 (s) cm⁻¹ with the error of margin of about ±12;about ±10; about ±8; about ±5; about ±3; about ±1; or less. In anotherembodiment, the Raman spectrum further comprises peaks at about 3003 (s)and about 521 (s) cm⁻¹ with the error of margin of about ±12; about ±10;about ±8; about ±5; about ±3; about ±1; or less. In one specificembodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monoedisylateexhibits a Raman spectrum that is substantially similar to FIG. 44. Inanother specific embodiment, the compound2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monoedisylate asdescribed in the above embodiments is(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamidemonoedisylate.

In one embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monooxalate exhibitsan Raman spectrum comprising peaks at about 2897 (s); about 1692 (s);and about 491 (m) cm⁻¹ with the error of margin of about ±12; about ±10;about ±8; about ±5; about ±3; about ±1; or less. In another embodiment,the Raman spectrum further comprises peaks at about 2955 (s), about 1443(s), and about 1252 (s) cm⁻¹ with the error of margin of about ±12;about ±10; about ±8; about ±5; about ±3; about ±1; or less. In onespecific embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monooxalate exhibitsa Raman spectrum that is substantially similar to FIG. 49. In anotherspecific embodiment, the compound2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monooxalate asdescribed in the above embodiments is(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monooxalate.

In one embodiment, the crystalline forms are characterized byDifferential Scanning calorimetry (DSC). The DSC thermogram is typicallyexpressed by a diagram plotting the normalized heat flow in units ofWatts/gram (“W/g”) versus the measured sample temperature in degree C.The DSC thermogram is usually evaluated for extrapolated onset and end(outset) temperatures, peak temperature, and heat of fusion. The singlemaximum value of a DSV thermogram is often used as the characteristicpeak to distinguish this crystalline structure from others.

Those skilled in the art recognize that the measurements of the DSCthermogram for a given crystalline form of the same compound will varywithin a margin of error. The values of a single maximum value,expressed in degree C., allow appropriate error margins. Typically, theerror margins are represented by “±”. For example, the single maximumvalue of about “53.09±2.0” denotes a range from about 53.09+2, i.e.,about 55.09, to about 53.09−2, i.e., about 51.09. Depending on thesample preparation techniques, the calibration techniques applied to theinstruments, human operational variations, and etc, those skilled in theart recognize that the appropriate error of margins for a single maximumvalue can be ±2.5; ±2; ±1.5; ±1; ±0.5; or less.

Additional details of the methods and equipment used for the DSCthermogram analysis are described in the Examples section.

In one embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide exhibits a DSCthermogram comprising a single maximum value at about 53.09±2.0° C. withthe error of margin of about ±2.5; about ±2; about ±1.5; about ±1; about±0.5; or less. In one specific embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide exhibits a DSCthermogram that is substantially similar to FIG. 6. In another specificembodiment, the compound2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide as described in theabove embodiments is(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide.

In one embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monosulfate exhibitsa DSC thermogram comprising a single maximum value at about 176.49±2.0°C. with the error of margin of about ±2.5; about ±2; about ±1.5; about±1; about ±0.5; or less. In one specific embodiment, the crystallineform of 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monosulfateexhibits a DSC thermogram that is substantially similar to FIG. 11. Inanother specific embodiment, the compound2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monosulfate asdescribed in the above embodiments is(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monosulfate.

In one embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide disulfate exhibits aDSC thermogram comprising a single maximum value at about 228.03±2.0° C.with the error of margin of about ±2.5; about ±2; about ±1.5; about ±1;about ±0.5; or less. In one specific embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide disulfate exhibits aDSC thermogram that is substantially similar to FIG. 14. In anotherspecific embodiment, the compound2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide disulfate asdescribed in the above embodiments is(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide disulfate.

In one embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide digluconate exhibitsa DSC thermogram comprising a single maximum value at about 182.33±2.0°C. with the error of margin of about ±2.5; about ±2; about ±1.5; about±1; about ±0.5; or less. In one specific embodiment, the crystallineform of 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide digluconateexhibits a DSC thermogram that is substantially similar to FIG. 20. Inanother specific embodiment, the compound2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide digluconate asdescribed in the above embodiments is(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide digluconate.

In one embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dimesylate exhibits aDSC thermogram comprising a single maximum value at about 180.77±2.0° C.with the error of margin of about ±2.5; about ±2; about ±1.5; about ±1;about ±0.5; or less. In one specific embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dimesylate exhibits aDSC thermogram that is substantially similar to FIG. 26A. In anotherspecific embodiment, the compound2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dimesylate asdescribed in the above embodiments is(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dimesylate.

In one embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide ditosylate exhibits aDSC thermogram comprising a single maximum value at about 191.85±2.0° C.with the error of margin of about ±2.5; about ±2; about ±1.5; about ±1;about ±0.5; or less. In one specific embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide ditosylate exhibits aDSC thermogram that is substantially similar to FIG. 31A. In anotherspecific embodiment, the compound2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide ditosylate asdescribed in the above embodiments is(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide ditosylate.

In one embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dinapsylate exhibitsa DSC thermogram comprising a single maximum value at about 185.56±2.0°C. with the error of margin of about ±2.5; about ±2; about ±1.5; about±1; about ±0.5; or less. In one specific embodiment, the crystallineform of 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dinapsylateexhibits a DSC thermogram that is substantially similar to FIG. 36A. Inanother specific embodiment, the compound2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dinapsylate asdescribed in the above embodiments is(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide dinapsylate.

In one embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monoedisylateexhibits a DSC thermogram comprising a single maximum value at about317.25±2.0° C. with the error of margin of about ±2.5; about ±2; about±1.5; about ±1; about ±0.5; or less. In one specific embodiment, thecrystalline form of 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamidemonoedisylate exhibits a DSC thermogram that is substantially similar toFIG. 41A. In another specific embodiment, the compound2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monoedisylate asdescribed in the above embodiments is(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamidemonoedisylate.

In one embodiment, the crystalline form of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monooxalate exhibitsa DSC thermogram comprising a single maximum value at about 234.32±2.0°C. with the error of margin of about ±2.5; about ±2; about ±1.5; about±1; about ±0.5; or less. In one specific embodiment, the crystallineform of 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monooxalateexhibits a DSC thermogram that is substantially similar to FIG. 46A. Inanother specific embodiment, the compound2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monooxalate asdescribed in the above embodiments is(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide monooxalate.

Additional methods of characterize the present crystalline forms aredescribed in the Example section of this application.

Pharmaceutical Formulations

In another embodiment, the present invention provides a pharmaceuticalcomposition comprising a therapeutically effective amount of acrystalline form of the present invention as the active ingredient,combined with a pharmaceutically acceptable excipient or carrier. Theexcipients are added to the formulation for a variety of purposes.

Diluents may be added to the formulations of the present invention.Diluents increase the bulk of a solid pharmaceutical composition, andmay make a pharmaceutical dosage form containing the composition easierfor the patient and care giver to handle. Diluents for solidcompositions include, for example, microcrystalline cellulose (e.g.,AVICEL), microtine cellulose, lactose, starch, pregelatinized starch,calcium carbonate, calcium sulfate, sugar, dextrates, dextrin, dextrose,dibasic calcium phosphate dihydrate, tribasic calcium phosphate, kaolin,magnesium carbonate, magnesium oxide, maltodextrin, mannitol,polymethacrylates (e.g., EUDRAGIT), potassium chloride, powderedcellulose, sodium chloride, sorbitol, and talc.

Solid pharmaceutical compositions that are compacted into a dosage form,such as a tablet, may include excipients whose functions include helpingto bind the active ingredient and other excipients together aftercompression. Binders for solid pharmaceutical compositions includeacacia, alginic acid, carbomer (e.g., carbopol), carboxymethylcellulosesodium, dextrin, ethyl cellulose, gelatin, guar gum, hydrogenatedvegetable oil, hydroxyethyl cellulose, hydroxypropyl cellulose (e.g.,KLUCEL), hydroxypropyl methyl cellulose (e.g., METHOCEL), liquidglucose, magnesium aluminum silicate, maltodextrin, methylcellulose,polymethacrylates, povidone (e.g., KOLLIDON, PLASDONE), pregelatinizedstarch, sodium alginate, and starch.

The dissolution rate of a compacted solid pharmaceutical composition inthe patient's stomach may be increased by the addition of a disintegrantto the composition. Disintegrants include alginic acid,carboxymethylcellulose calcium, carboxymethylcellulose sodium (e.g.,AC-DI-SOL and PRIMELLOSE), colloidal silicon dioxide, croscarmellosesodium, crospovidone (e.g., KOLLIDON and POLYPLASDONE), guar gum,magnesium aluminum silicate, methyl cellulose, microcrystallinecellulose, polacrilin potassium, powdered cellulose, pregelatinizedstarch, sodium alginate, sodium starch glycolate (e.g., EXPLOTAB), andstarch.

Glidants can be added to improve the flowability of a non-compactedsolid composition and to improve the accuracy of dosing. Excipients thatmay function as glidants include colloidal silicon dioxide, magnesiumtrisilicate, powdered cellulose, starch, talc, and tribasic calciumphosphate.

When a dosage form such as a tablet is made by the compaction of apowdered composition, the composition is subjected to pressure from apunch and dye. Some excipients and active ingredients have a tendency toadhere to the surfaces of the punch and dye, which can cause the productto have pitting and other surface irregularities. A lubricant can beadded to the composition to reduce adhesion and ease the release of theproduct from the dye. Lubricants include magnesium stearate, calciumstearate, glyceryl monostearate, glyceryl palmitostearate, hydrogenatedcastor oil, hydrogenated vegetable oil, mineral oil, polyethyleneglycol, sodium benzoate, sodium lauryl sulfate, sodium stearyl fumarate,stearic acid, talc, and zinc stearate.

Flavoring agents and flavor enhancers make the dosage form morepalatable to the patient. Common flavoring agents and flavor enhancersfor pharmaceutical products that may be included in the composition ofthe present invention include maltol, vanillin, ethyl vanillin, menthol,citric acid, fumaric acid, ethyl maltol, and tartaric acid.

Solid and liquid compositions may also be dyed using anypharmaceutically acceptable colorant to improve their appearance and/orfacilitate patient identification of the product and unit dosage level.

The present invention is not intended to encompass true solutions ofatomoxetine hydrochloride whereupon the crystal structure of the novelcrystalline forms and the properties that characterize the novelcrystalline forms of atomoxetine hydrochloride of the present inventionare lost. However, the use of the novel forms to prepare such solutions(e.g., so as to deliver atomoxetine hydrochloride in a liquidpharmaceutical formulation) is considered to be within the contemplationof the invention.

In liquid pharmaceutical compositions prepared using the crystallineforms of the present invention, atomoxetine hydrochloride and any othersolid excipients are dissolved or suspended in a liquid carrier such aswater, vegetable oil, alcohol, polyethylene glycol, propylene glycol, orglycerin.

Liquid pharmaceutical compositions may contain emulsifying agents todisperse uniformly throughout the composition an active ingredient orother excipient that is not soluble in the liquid carrier. Emulsifyingagents that may be useful in liquid compositions of the presentinvention include, for example, gelatin, egg yolk, casein, cholesterol,acacia, tragacanth, chondrus, pectin, methyl cellulose, carbomer,cetostearyl alcohol, and cetyl alcohol.

Liquid pharmaceutical compositions may also contain a viscosityenhancing agent to improve the mouth-feel of the product and/or coat thelining of the gastrointestinal tract. Such agents include acacia,alginic acid bentonite, carbomer, carboxymethylcellulose calcium orsodium, cetostearyl alcohol, methyl cellulose, ethylcellulose, gelatinguar gum, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, maltodextrin, polyvinyl alcohol, povidone, propylenecarbonate, propylene glycol alginate, sodium alginate, sodium starchglycolate, starch tragacanth, and xanthan gum.

Sweetening agents such as sorbitol, saccharin, sodium saccharin,sucrose, aspartame, fructose, mannitol, and invert sugar may be added toimprove the taste.

Preservatives and chelating agents such as alcohol, sodium benzoate,butylated hydroxyl toluene, butylated hydroxyanisole, andethylenediamine tetraacetic acid may be added at levels safe foringestion to improve storage stability.

A liquid composition may also contain a buffer such as gluconic acid,lactic acid, citric acid or acetic acid, sodium gluconate, sodiumlactate, sodium citrate, or sodium acetate. Selection of excipients andthe amounts used may be readily determined by the formulation scientistbased upon experience and consideration of standard procedures andreference works in the field.

The solid compositions of the present invention include powders,granulates, aggregates and compacted compositions. The dosages includedosages suitable for oral, buccal, rectal, parenteral (includingsubcutaneous, intramuscular, and intravenous), inhalant and ophthalmicadministration. Although the most suitable administration in any givencase will depend on the nature and severity of the condition beingtreated, the most preferred route of the present invention is oral. Thedosages may be conveniently presented in unit dosage form and preparedby any of the methods well-known in the pharmaceutical arts.

Dosage forms include solid dosage forms like tablets, powders, capsules,suppositories, sachets, troches and lozenges, as well as liquid syrups,suspensions and elixirs.

The dosage of STRATTERA may be used as guidance. The oral dosage form ofthe present invention is preferably in the form of an oral capsule ortablet having a dosage of about 5 mg to about 160 mg in total weightincluding the active ingredient and other excipients, more preferablyfrom about 20 mg to about 80 mg, and most preferably capsules or tabletsof 10, 18, 20, 25, 40, 60 and 80 mg. Daily dosages may include 1, 2, ormore capsules per day.

The dosage form of the present invention may be a capsule containing thecomposition, preferably a powdered or granulated solid composition ofthe invention, within either a hard or soft shell. The shell may be madefrom gelatin and optionally contain a plasticizer such as glycerin andsorbitol, and an opacifying agent or colorant.

A composition for tableting or capsule filling may be prepared by wetgranulation. In wet granulation, some or all of the active ingredientsand excipients in powder form are blended and then further mixed in thepresence of a liquid, typically water, that causes the powders to clumpinto granules. The granulate is screened and/or milled, dried and thenscreened and/or milled to the desired particle size. The granulate maythen be tableted, or other excipients may be added prior to tableting,such as a glidant and/or a lubricant.

A tableting composition may be prepared conventionally by dry blending.For example, the blended composition of the actives and excipients maybe compacted into a slug or a sheet and then comminuted into compactedgranules. The compacted granules may subsequently be compressed into atablet.

As an alternative to dry granulation, a blended composition may becompressed directly into a compacted dosage form using directcompression techniques. Direct compression produces a more uniformtablet without granules. Excipients that are particularly well suitedfor direct compression tableting include microcrystalline cellulose,spray dried lactose, dicalcium phosphate dihydrate and colloidal silica.The proper use of these and other excipients in direct compressiontableting is known to those in the art with experience and skill inparticular formulation challenges of direct compression tableting.

A capsule filling of the present invention may comprise any of theaforementioned blends and granulates that were described with referenceto tableting, however, they are not subjected to a final tableting step.

The active ingredient and excipients may be formulated into compositionsand dosage forms according to methods known in the art.

It is not necessary that the formulations of the present inventioncontain only one crystalline form of atomoxetine hydrochloride. Thecrystalline forms of the present invention may be used in pharmaceuticalformulations or compositions as single components or mixtures togetherwith other crystalline forms of atomoxetine hydrochloride or withamorphous atomoxetine hydrochloride. However, it is preferred that thepharmaceutical formulations or compositions of the present inventioncontain 25-100% by weight, especially 50-100% by weight, of at least oneof the novel forms, based on the total amount of atomoxetinehydrochloride in the formulation or composition. Preferably, such anamount of the novel crystalline form of atomoxetine hydrochloride is75-100% by weight, especially 90-100% by weight. Highly preferred is anamount of 95-100% by weight.

Therapeutic Use

The present invention also provides treatment of disorders involvingdegradation or dysfunction of cells expressing p75.

In one aspect, there is provided a method for activating p75 receptorscomprising contacting a cell containing a p75 receptor with the presentcrystalline form. Additionally disclosed are methods for treatingnervous system disorders including (but not limited to) Alzheimer'sdisease, Parkinson's disease, Huntington's disease, stroke, traumaticbrain injury, spinal cord injury, epilepsy, multiple sclerosis,amyotrophic lateral sclerosis, neuropathies, myopathies and variousforms of retinal degeneration, based on the ability of the crystallineforms of the present invention to target p75 receptors expressed byneurons.

Additionally disclosed are methods for treating nervous system disordersincluding (and not limited to) multiple sclerosis, spinal cord injuryand perinatal anoxia, based on the ability of the crystalline forms ofthe present application to target p75 receptors expressed byoligodendrocytes.

Further disclosed are methods for treating diseases other than those ofthe nervous system, particularly preventing loss of hair follicle cellsand thereby preventing hair loss; preventing hepatic cirrhosis andpromote liver regeneration; to regulate angiogenesis and promoteneovascularization in the setting of diabetic wounds or other ischemicsettings; to prevent cardiomyopathy by preventing myocardial cell lossor by stimulating growth of new cardiomyocytes either in the setting ofischemia or after myocardial infarction; and to inhibit tumor cellgrowth. In addition p75 is expressed by stem cells and is known toregulate stem cell growth; therefore, p75 ligands can be used to promotestem cell growth as part of a strategy to promote tissue and organregeneration.

The present invention also provides methods of treatingneurodegenerative and other disorders or conditions in a subject. Moreparticularly, the methods of the present invention involveadministration of a crystalline form in a subject to treat aneurodegenerative disorder or other disorder or condition. Thecrystalline form can be administered in an amount effective to inducesurvival signaling and/or inhibit proNGF-induced cell death, which hasbeen determined to be associated with neurodegenerative and otherdisorders. The terms “subject” and “patient” are used interchangeablythroughout the present application.

The condition to be treated can be any condition which is mediated, atleast in part, by binding of neurotrophins to p75^(NTR). Such conditionsinclude, but are not limited to, Alzheimer's disease, Huntington'sdisease, Pick's disease, amyotrophic lateral sclerosis, epilepsy,Parkinson's disease, spinal cord injury, stroke, hypoxia, ischemia,brain injury, diabetic neuropathy, peripheral neuropathy, nervetransplantation, multiple sclerosis, peripheral nerve injury, and hairloss.

The present crystalline form can be used to treat neural degeneration,including preventing neurodegeneration such as, for example,neurodegeneration caused by chemotherapy and/or neurodegenerativedisorders, as well as other conditions such as inducing hair folliclecell survival caused by, for example, chemotherapy.

The present invention further provides for novel methods of facilitatingcell survival. Representative cells include, but are not limited to,septal, hippocampal, cortical, sensory, sympathetic, motor neurons, hairfollicle cells, progenitor, and stem cells. Generally, such cellsinclude neurons, oligodendrocytes and hair follicle cells. Specifically,the methods comprise treating a cell with the present crystalline form,whereby the compound induces survival signaling and inhibitsproNGF-induced cell death.

The present invention also discloses a method of administering thepresent crystalline form in order to ameliorate a condition mediated byp75^(NTR) binding in a subject. The method can comprise the step ofadministering to a subject an effective amount of a crystalline form ofthe present invention.

As used herein, administering can be effected or performed using any ofthe various methods known to those skilled in the art. The crystallineform can be administered, for example, subcutaneously, intravenously,parenterally, intraperitoneally, intradermally, intramuscularly,topically, enteral (e.g., orally), rectally, nasally, buccally,sublingually, vaginally, by inhalation spray, by drug pump or via animplanted reservoir in dosage formulations containing conventionalnon-toxic, physiologically acceptable carriers or vehicles.

Further, the presently disclosed crystalline forms can be administeredto a localized area in need of treatment. This can be achieved by, forexample, and not by way of limitation, local infusion during surgery,topical application, transdermal patches, by injection, by catheter, bysuppository, or by implant (the implant can optionally be of a porous,non-porous, or gelatinous material), including membranes, such assialastic membranes or fibers.

The form in which the crystalline form is administered (e.g., syrup,elixir, capsule, tablet, foams, emulsion, gel, etc.) will depend in parton the route by which it is administered. For example, for mucosal(e.g., oral mucosa, rectal, intestinal mucosa, bronchial mucosa)administration, nose drops, aerosols, inhalants, nebulizers, eye dropsor suppositories can be used. The crystalline form can also be used tocoat bioimplantable materials to enhance neurite outgrowth, neuralsurvival, or cellular interaction with the implant surface. Thecrystalline forms and agents disclosed herein can be administeredtogether with other biologically active agents, such as analgesics,anti-inflammatory agents, anesthetics and other agents which can controlone or more symptoms or causes of a p75^(NTR)-mediated condition.

Additionally, administration can comprise administering to the subject aplurality of dosages over a suitable period of time. Such administrationregimens can be determined according to routine methods, upon a reviewof the instant disclosure.

The crystalline forms of the present application can be employed as thesole active agent in a pharmaceutical or can be used in combination(e.g., administered proximate in time to each other or even in the sameformulation) with other active ingredients, e.g., neurotrophins, orother factors or drugs which can facilitate neural survival or axonalgrowth in neurodegenerative diseases, including but not limited toamyloid-β inhibitors, acetylcholinesterase inhibitors,butyrylcholinesterase inhibitors, and N-methyl-D-aspartate subtype ofglutamate receptor antagonists.

Crystalline forms of the invention are generally administered in a doseof about 0.01 mg/kg/dose to about 100 mg/kg/dose. Alternately the dosecan be from about 0.1 mg/kg/dose to about 10 mg/kg/dose; or about 1mg/kg/dose to 10 mg/kg/dose. In some dosages, the crystalline formsdisclosed herein are administered at about 5 mg/kg/dose. Time releasepreparations may be employed or the dose may be administered in as manydivided doses as is convenient. When other methods are used (e.g.intravenous administration), crystalline forms are administered to theaffected tissue at a rate from about 0.05 to about 10 mg/kg/hour,alternately from about 0.1 to about 1 mg/kg/hour. Such rates are easilymaintained when these crystalline forms are intravenously administeredas discussed herein. Generally, topically administered formulations areadministered in a dose of about 0.5 mg/kg/dose to about 10 mg/kg/doserange. Alternately, topical formulations are administered at a dose ofabout 1 mg/kg/dose to about 7.5 mg/kg/dose or even about 1 mg/kg/dose toabout 5 mg/kg/dose.

A range of from about 0.1 to about 100 mg/kg is appropriate for a singledose. Continuous administration is appropriate in the range of about0.05 to about 10 mg/kg. Topical administration is appropriate forconditions such as hair loss or wound revascularization.

Drug doses can also be given in milligrams per square meter of bodysurface area rather than body weight, as this method achieves a goodcorrelation to certain metabolic and excretionary functions. Moreover,body surface area can be used as a common denominator for drug dosage inadults and children as well as in different animal species (Freireich etal., (1966) Cancer Chemother Rep. 50, 219-244). Briefly, to express amg/kg dose in any given species as the equivalent mg/sq m dose, thedosage is multiplied by the appropriate km factor. In an adult human,100 mg/kg is equivalent to 100 mg/kg×37 kg/sq m=3700 mg/m².

Insofar as the crystalline forms disclosed herein can take the form of amimetic or fragment thereof, it is to be appreciated that the potency,and therefore dosage of an effective amount can vary. However, oneskilled in the art can readily assess the potency of a crystalline formof the type presently envisioned by the present application.

In settings of a gradually progressive nervous system disorder,crystalline forms of the present application are generally administeredon an ongoing basis. In certain settings administration of a crystallineform disclosed herein can commence prior to the development of diseasesymptoms as part of a strategy to delay or prevent the disease. In othersettings a crystalline form disclosed herein is administered after theonset of disease symptoms as part of a strategy to slow or reverse thedisease process and/or part of a strategy to improve cellular functionand reduce symptoms. Crystalline forms have been developed that crossthe blood brain barrier and hence would be delivered by oraladministration or by other peripheral routes. Crystalline forms that donot cross the blood brain barrier are applied for targets outside of thecentral nervous system. For targets and tissues outside of the nervoussystem, crystalline forms are applied in either acute or chronicsettings by other oral or directed target administration such as bytopical application.

It will be appreciated by one of skill in the art that dosage range willdepend on the particular crystalline form, and its potency. The dosagerange is understood to be large enough to produce the desired effect inwhich the neurodegenerative or other disorder and the symptomsassociated therewith are ameliorated and/or survival of the cells isachieved, but not be so large as to cause unmanageable adverse sideeffects. It will be understood, however, that the specific dose levelfor any particular patient will depend on a variety of factors includingthe activity of the specific crystalline form employed; the age, bodyweight, general health, sex and diet of the individual being treated;the time and route of administration; the rate of excretion; other drugswhich have previously been administered; and the severity of theparticular disease undergoing therapy, as is well understood by thoseskilled in the art. The dosage can also be adjusted by the individualphysician in the event of any complication. No unacceptabletoxicological effects are expected when crystalline forms disclosedherein are used in accordance with the present application.

An effective amount of the crystalline forms disclosed herein compriseamounts sufficient to produce a measurable biological response. Actualdosage levels of active ingredients in a therapeutic crystalline form ofthe present application can be varied so as to administer an amount ofthe active crystalline form that is effective to achieve the desiredtherapeutic response for a particular subject and/or application.Preferably, a minimal dose is administered, and the dose is escalated inthe absence of dose-limiting toxicity to a minimally effective amount.Determination and adjustment of a therapeutically effective dose, aswell as evaluation of when and how to make such adjustments, are knownto those of ordinary skill in the art.

Further with respect to the methods of the present application, apreferred subject is a vertebrate subject. A preferred vertebrate iswarm-blooded; a preferred warm-blooded vertebrate is a mammal. Thesubject treated by the presently disclosed methods is desirably a human,although it is to be understood that the principles of the presentapplication indicate effectiveness with respect to all vertebratespecies which are to included in the term “subject.” In this context, avertebrate is understood to be any vertebrate species in which treatmentof a neurodegenerative disorder is desirable. As used herein, the term“subject” includes both human and animal subjects. Thus, veterinarytherapeutic uses are provided in accordance with the presentapplication.

As such, the present application provides for the treatment of mammalssuch as humans, as well as those mammals of importance due to beingendangered, such as Siberian tigers; of economic importance, such asanimals raised on farms for consumption by humans; and/or animals ofsocial importance to humans, such as animals kept as pets or in zoos orfarms. Examples of such animals include but are not limited to:carnivores such as cats and dogs; swine, including pigs, hogs, and wildboars; ruminants and/or ungulates such as cattle, oxen, sheep, giraffes,deer, goats, bison, and camels; and horses. Also provided is thetreatment of birds, including the treatment of those kinds of birds thatare endangered and/or kept in zoos, as well as fowl, and moreparticularly domesticated fowl, i.e., poultry, such as turkeys,chickens, ducks, geese, guinea fowl, and the like, as they are also ofeconomical importance to humans. Thus, also provided is the treatment oflivestock, including, but not limited to, domesticated swine, ruminants,ungulates, horses (including race horses), poultry, and the like.

The following examples further illustrate the present invention butshould not be construed as in any way limiting its scope.

EXAMPLES

Analytical Methods—various analytical methods, as described below, wereapplied to the present crystalline forms and their precursors tocharacterize their physiochemical properties.

Microscopy:

A Zeiss Universal microscope configured with a polarized visible lightsource and polarizable analyzer was used to evaluate the opticalproperties of the samples. Specimens were typically mounted on amicroscope slide with a drop of immersion oil and a cover glass.Magnification was typically 100×. Observations of particle/crystal sizeand shape were recorded. The presence of birefringence was also noted.

Molecular Spectroscopy—¹H-NMR:

Samples were prepared by dissolving 1-10 mg in dimethylsulfoxide(DMSO)-d₆ with 0.05% (v/v) tetramethylsilane (TMS). Spectra werecollected at ambient temperature on a Bruker Avance III 400 MHz FT-NMRspectrometer and Bruker Topspin software (version 2.1). Prior to eachsample analysis, the magnetic field surrounding the sample was optimizedby an automated shimming program.

Differential Scanning Calorimetry (DSC):

DSC data were collected on a TA Instruments DSC. In general, samples inthe mass range of 1 to 10 mg were crimped in aluminum sample pans andscanned from 25 to about 250° C. or 300° C. at 10° C./minute using anitrogen purge of 50 mL/min.

Thermogravimetric Analysis (TGA):

TGA data were collected on a TA Instruments 2950 TGA. In general,samples in the mass range of 2 to 10 mg were placed in an open,pre-tared platinum sample pan and scanned from 25 to about 150° C. at10° C./minute using a nitrogen purge at 100 mL/min.

Hot Stage Microscopy (HSM):

A Zeiss Universal microscope configured with a polarized visible lightsource and a Linkam hot stage accessory was used. Specimens were mountedon a microscope slide with a cover glass. Magnification was typically6.3×. Samples were heated from 25° C. to about 250° C. at 10 or 2°C./minute. Linksys 32 temperature control and data capture softwaresystem (Linkam Scientific Instruments Ltd, Waterfield, Tadworth, SurreyKT20 SLR, UK). Observations of phase change, recrystallization,evolution of bubbles, etc. were recorded.

Raman Spectroscopy:

Raman spectra were obtained with a Thermo DXR dispersive Ramanspectrometer using laser excitation at 780 nm. Spectra were acquiredfrom 3300 to 300 cm⁻¹ (Raman shift) using a 400 line/mm wide-rangedispersive grating and from 1850 to 300 cm⁻¹ (Raman shift) using an 830line/mm high resolution dispersive grating. Each scan was 5 sec, and 64scans were collected for each analysis. Samples were analyzed as bulkpowders and from 96-well plate experiments.

X-Ray Powder Diffraction (XRD):

X-ray powder diffraction patterns were obtained using a Bruker D8Discovery diffractometer equipped with an XYZ stage, laser videomicroscope for positioning, and a two dimensional HiStar area Detector.Collection times were nominally 60 seconds. A Cu Kα radiation 1.5406angstrom source operating at 40 kV and 40 mA was used to irradiatesamples. The X-ray optics consists of a Gobel mirror coupled with apinhole collimator of 0.5 mm. Theta-theta continuous scans were employedwith a sample-detector distance of approximately 15 cm, which gives aneffective 20 range of 4-40° C. Samples were mounted in low backgroundquartz plates.

Solubility:

Milligram size quantities of each sample were placed into a vial. Waterwas added and the vials were stirred for a few minutes, followed byvisual observation for remaining solids. The solvent was incrementallyadded until the solids were dissolved, or a maximum volume of solventwas added and the experiment was terminated. It turned out that all thesalts tested were highly water soluble.

Hygroscopicity—Dynamic Vapor Sorption (DVS):

Samples were analyzed using an automated dynamic vapor sorptionanalyzer. The sample (about 1-10 mg) was dried in the instrument 0% RHfor 6 hours. The samples were subjected to 0 to 95% RH back to 5% RH at25° C. in 5% RH steps.

Stability:

The scaled up salts and free base were challenged by heat (solids storedat 25 and 60° C. for 1 week), oxidation (solids stored in oxygenheadspace at 25° C. for 1 week), light (solids exposed to ≥1×ICH UVconfirmatory conditions), and solutions (HPLC diluent) at 25 and 40° C.for 1 week. These samples were analyzed, along with unstressed controls,by HPLC to characterize their stability.

HPLC Analysis:

Crystalline forms (i.e., salts and free base) of the present inventionwere analyzed by total area normalization (TAN). The samples weredissolved in 1:1 Acetonitrile (ACN):Water (H₂O) at a concentration of0.5 mg/mL.

HPLC Conditions:

HPLC Column: XBridge Shield RP18, 3.5 um, 4.6×100 mm

Column Temp: 30° C.

Auto sampler Flush: Water: CAN (1:1)

Flow Rate: 1 mL/min

Injection Volume: 15 mL

UV Detection: 205 nm w/spectral acquisition

Mobile Phase: A—H₂O pH 10 with NH₄OH

-   -   B—ACN        Gradient Pump Program:

Step Time % A % B (minutes) (pH 10 aq) (ACN) Curve 0.5 90.0 10.0 0.0 5.090.0 10.0 0.0 10.0 10.0 90.0 1.0 3.0 10.0 90.0 0.0 6.0 90.0 10.0 0.0

Example 1. Characterization of the Amorphous Dihydrochloride Salt of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide

The free base compound of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide can be prepared fromisoleucine by synthetic methods known to one skilled in the art.Standard procedures and chemical transformation and related methods arewell known to one skilled in the art, and such methods and procedureshave been described, for example, in standard references such asFiesers' Reagents for Organic Synthesis, John Wiley and Sons, New York,N.Y., 2002; Organic Reactions, vols. 1-83, John Wiley and Sons, NewYork, N.Y., 2006; March J. and Smith M., Advanced Organic Chemistry, 6thed., John Wiley and Sons, New York, N.Y.; and Larock R. C.,Comprehensive Organic Transformations, Wiley-VCH Publishers, New York,1999. All texts and references cited herein are incorporated byreference in their entirety. Other related synthetic methods can befound in U.S. Patent Application Publication Nos. 2006/024072 and2007/0060526, the contents of which are herein incorporated by referencein their entirety for all purposes. The amorphous dihydrochloride(di-HCl) salt of 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide canbe prepared by mixing two molar equivalents of HCl with one molarequivalent of 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide inappropriate solvent(s) and then separating the di-HCl salt from thesolvent(s) mixture.

The amorphous di-HCl salt of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide was analyzed via themethods as described above. The XRD analysis indicated it wasamorphous/low ordered as shown in FIG. 1. The DSC thermogram exhibited abroad endotherm with onset temperature 37° C. and peak temperature 74°C. and an enthalpy value of ΔH=80 J/g. The TGA thermogram indicated thedi-HCl salt is anhydrous and starts to decompose after about 200° C. Anoverlay of DSC and TGA thermograms are shown in FIG. 2. The moisturesorption-desorption isotherm of the di-HCl salt (FIGS. 3A and 3B) wascollected using dynamic vapor sorption (DVS) analysis. The material didnot adsorb much moisture from 0% to 20% RH, then it showed steadysorption up to 140 wt % moisture at 95% RH (likely deliquescence). Thissample showed rapid desorption from 95% to 70% RH and then continuesdesorbing at a relatively slower pace to a mass about 5 wt % greaterthan the original value at 0% RH. This sample shows a small hysteresisbetween the sorption and desorption phase. Overall this material isquite hygroscopic. The crude solubility of the di-HCl salt in waterwas >30 mg/mL. The proton NMR spectrum of the amorphous di-HCl salt isshown in FIG. 4.

Example 2. Preparation of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide (Free Base)

Five grams of 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide di-HClsalt was dissolved in 150 mL of ethanol. Sodium bicarbonate (5.3 g),dissolved in 100 mL of HPLC water, was added to this solution. The mixedsolution was sonicated for ˜10 minutes. This solution was concentratedusing a rotovap, and the residue was dissolved in 300 mL of methylenechloride. This solution was passed through a short plug of carbonatebonded silica gel. This solution was concentrated using rotovap and theresidue was lyophilized to dry, resulting in 3.6 g of the free base as awhite solid. Proton NMR, C-13 NMR and LC/MS confirmed the structure ofthis material as the free base of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide.

In the process of converting the di-HCl salt to free base, the samplewas lyophilized to avoid formation of oil. XRD analysis of thelyophilized free base surprisingly revealed it was crystalline, as shownin FIG. 5. The DSC thermogram exhibited an endotherm with extrapolatedonset temperature 51° C. and peak temperature 53° C. and an enthalpyvalue of ΔH_(f)=104 J/g. The TGA thermogram shows less than 0.6 wt %loss at 105° C., suggesting it was solvent free. An overlay of the DSCand TGA thermograms can be seen in FIG. 6. The crude solubility of freebase in water was >30 mg/mL. The proton NMR was consistent with the freebase. The NMR and Raman spectra are shown in FIGS. 7 and 8A and 8B,respectively. The moisture sorption-desorption isotherm (FIGS. 9A and9B) was collected using dynamic vapor sorption (DVS) analysis. Thesample did not adsorb much moisture content from 0% to 45% RH under theexperimental conditions. Above 45% RH the sample appears to adsorbmoisture of ˜10 wt % from 45% to 50% RH followed by rapid sorption up to96 wt % moisture at 95% RH. In the desorption phase, the free base showsa rapid desorption from 95% to 80% RH, then the sample desorbs at arelatively slow pace to the original weight at 0% RH. The sample mayform a hydrate near 45% RH. The putative hydrate appears to deliquesceresulting in an amorphous glass by the end of the scan.

Example 3. Preparation of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide Monosulfate

The free base as prepared in Example 2 was dissolved in methanol, and aportion of this solution was transferred to provide 2 mg equivalent offree base. Sulfuric acid was dissolved in THF or methanol. Equal molarportions of the free base and acid solutions were mixed, and theresulting mixture solutions were dried under nitrogen purge at ambienttemperature to provide the desired monosulfate salts as dry solids. Theproduct was slurried in 2-propanol to increase the crystallinity.

XRD indicated the solids are crystalline (FIG. 10) and exhibited adifferent pattern from the free base. The DSC (FIG. 11) shows a smallbroad endotherm with peak temperature 76° C., then the broad exothermwith peak temperature 176° C. The hot stage microscopy data suggest thematerial decomposes near 165° C. The Raman spectrum of this sample isgiven in FIGS. 12A and 12B.

Example 4. Preparation of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide Disulfate

The free base as prepared in Example 2 was dissolved in methanol, and aportion of this solution was transferred to provide 25 mg equivalent offree base. Sulfuric acid was dissolved or suspended in water, methanol,or acetonitrile. The free base and sulfuric acid solutions/suspensions(providing 1:2 molar ratio of free base and sulfuric acid) were mixed.The resulting mixture solutions/suspensions were slurried in 2-propanolat ambient temperature to obtain clear solutions. The clear solutionswere evaporated under nitrogen at ˜1.5 psi to provide suspensions whichwere subsequently filtered to provide the disulfate salts as solids.

XRD indicated the disulfate material is crystalline as shown in FIG. 13and is different from free base. The DSC (FIG. 14) shows a broadendotherm with extrapolated onset temperature of 210° C., peaktemperature of 228° C., which appears to be accompanied bydecomposition. The TGA (FIG. 15) shows disulfate material has less than0.7 wt % loss at 105° C., indicating the isolated sample was dry. Hotstage microscopy data revealed the material completely melted near 220°C. followed by immediate discoloration and the formation of bubbles,confirming the material is decomposing upon melting. The moisturesorption-desorption isotherm (FIGS. 16A and 16B) was collected usingdynamic vapor sorption (DVS) analysis. The disulfate does not sorbs muchwater from 0% to 60% RH under the experimental conditions, then it showsrapid sorption up to 140 wt % water at 95% RH. In the desorption phase,the disulfate material shows a rapid desorption from 95% to 80% RH, thenthe sample desorbs at a relatively slow pace to a mass about 4 wt %greater than the original value at 0% RH. The behavior of this samplewas similar to all the other samples. Apparent deliquescence at highhumidity followed by glass formation upon evaporation. A hydrate mayalso form near 60% RH. Some additional scans stopping at humidifiesbefore deliquescence may yield some additional insight into the behaviorof the putative hydrate. Proton NMR and Raman spectra of this sample aregiven in FIGS. 17 and 18A and 18B, respectively. The disulfate was foundto have high solubility in water (>3M/mL) at ambient temperature.

Example 5. Preparation of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide Digluconate

The digluconate salt was prepared by using the same procedure describedin Example 3 except that sulfuric acid was replaced by gluconic acid andthe molar ratio of the free base to gluconic acid is 1:2.

Alternatively, the free base as prepared in Example 2 was dissolved inmethanol, and a portion of this solution was transferred to provide 2 mgequivalent of free base. Gluconic acid was dissolved or suspended inEtOH/Heptane or THF/Heptane. The free base and gluconic acidsolutions/suspensions (providing 1:2 molar ratio of free base andgluconic acid) were mixed, and the resulting mixture solutions weredried under nitrogen purge at ambient temperature to provide the desireddigluconate salts as dry powdery solids.

XRD indicated the material is crystalline and exhibits a differentpattern from the free base as shown in FIG. 19. The DSC (FIG. 20) showsa small but sharp endotherm with an extrapolated onset of 50° C.,followed by a sharp melting endotherm with an extrapolated onset of 180°C. which was followed by decomposition. The TGA (FIG. 21) shows a 0.5 wt% loss at about 105° C., suggesting the salt specimen was relativelydry. Hot stage microscopy data suggest a possible phase transformationat about 50° C. The material was observed to melt at about 178° C.Additional studies to confirm that the 50° C. endotherm is a solidtransformation and not simply melting of residual free base should beconsidered. The moisture sorption-desorption isotherm (FIGS. 22A and22B) was collected using dynamic vapor sorption (DVS) analysis. Thedigluconate salt did not adsorb much moisture from 0% to 45% RH underthe experimental conditions, then it shows rapid sorption behavior up to110 wt % moisture at 95% RH. In the desorption phase, the digluconatesalt shows two distinct phases: rapid desorption from 95% to 65% RH,then the sample desorbs at a relatively slow pace to a mass about 4 wt %greater than the original value at 0% RH. This material appears to havedeliquesced and then evaporated to a glassy substance during thedesorption segment. The proton NMR and Raman spectra of the digluconatesalt sample are shown in FIGS. 23 and 24A and 24B respectively. Thedigluconate salt was found to have high solubility in water (>30 mg/mL)like all of the specimens examined during the current study.

Example 6. Preparation of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide Dimesylate

The dimesylate salt was prepared by using the same procedure describedin Example 3 except that sulfuric acid was replaced by methanesulfonicacid and the molar ratio of the free base to methanesulfonic acid is1:2.

Alternatively, the free base as prepared in Example 2 was dissolved inmethanol, and a portion of this solution was transferred to provide 2 mgequivalent of free base. Methanesulfonic acid was dissolved or suspendedin EtOH/Heptane or THF/Heptane. The free base and methanesulfonic acidsolutions/suspensions (providing 1:2 molar ratio of free base andmethanesulfonic acid) were mixed, and the resulting mixture solutionswere dried under nitrogen purge at ambient temperature to provide thedesired dimesylate salts as dry powdery solids.

XRD indicated the material is nicely crystalline and exhibits adifferent pattern from the free base, as shown in FIG. 25. The DSC (FIG.26A) shows a sharp melting endotherm with an extrapolated onset of 180°C. which was followed by decomposition at approximately 250° C. The TGA(FIG. 26B) shows a 0.5 wt % loss at about 105° C., suggesting the saltspecimen was relatively dry. Hot stage microscopy data suggest thematerial was observed to melt at about 178° C. The moisturesorption-desorption isotherm (FIGS. 27A and 27B) was collected usingdynamic vapor sorption analysis. The dimesylate salt did not adsorb muchmoisture from 0% to 55% RH under the experimental conditions, then itshows rapid sorption behavior up to 110 wt % moisture at 95% RH. In thedesorption phase, the dimesylate salt shows two distinct phases: rapiddesorption from 95% to 65% RH, then the sample desorbs at a relativelyslow pace to a mass about 3 wt % greater than the original value at 0%RH. The proton NMR and Raman spectra of the dimesylate salt sample areshown in FIGS. 28 and 29, respectively. The dimesylate salt was found tohave high solubility in water (≥28 mg/mL).

Example 7. Preparation of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide Ditosylate

The ditosylate salt was prepared by using the same procedure describedin Example 3 except that sulfuric acid was replaced by p-toluenesulfonicacid and the molar ratio of the free base to p-toluenesulfonic acid is1:2.

Alternatively, the free base as prepared in Example 2 was dissolved inmethanol, and a portion of this solution was transferred to provide 2 mgequivalent of free base. Toluenesulfonic acid was dissolved or suspendedin EtOH/Heptane or THF/Heptane. The free base and p-toluenesulfonic acidsolutions/suspensions (providing 1:2 molar ratio of free base andp-toluenesulfonic acid) were mixed, and the resulting mixture solutionswere dried under nitrogen purge at ambient temperature to provide thedesired ditosylate salts as dry powdery solids.

XRD indicated the material is nicely crystalline and exhibits adifferent pattern from the free base, as shown in FIG. 30. The DSC (FIG.31A) shows a sharp melting endotherm with an extrapolated onset of 191°C. with a stable baseline. The TGA (FIG. 31B) shows approximately 0.2 wt% loss at about 105° C., suggesting the salt specimen was relativelydry. Hot stage microscopy data revealed the material melted at about189° C. The moisture sorption-desorption isotherm (FIGS. 32A and 32B)collected using dynamic vapor sorption (DVS) analysis, did not adsorbmuch moisture from 0% to 80% RH under the experimental conditions,followed by a rapid sorption behavior up to 30 wt % moisture at 90% RH.In the desorption phase, this salt lost water rapidly at first thenslowed down over the 70 to 20% RH range. This sample may form hydratesat high humidity. Additional studies should be done to examine thenature of this salt form. The proton NMR and Raman spectra of theditosylate salt sample are shown in FIGS. 33 and 34, respectively. Theditosylate salt was found to have a low solubility in water (0.5-0.7mg/mL) relative to the free base.

Example 8. Preparation of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide Dinapsylate

The dinapsylate salt was prepared by using the same procedure describedin Example 3 except that sulfuric acid was replaced by2-naphthalenesulfonic acid and the molar ratio of the free base to2-naphthalenesulfonic acid is 1:2.

Alternatively, the free base as prepared in Example 2 was dissolved inmethanol, and a portion of this solution was transferred to provide 2 mgequivalent of free base. 2-Naphthalenesulfonic acid was dissolved orsuspended in EtOH/Heptane or THF/Heptane. The free base and2-naphthalenesulfonic acid solutions/suspensions (providing 1:2 molarratio of free base and 2-naphthalenesulfonic acid) were mixed, and theresulting mixture solutions were dried under nitrogen purge at ambienttemperature to provide the desired dinapsylate salts as dry powderysolids.

XRD indicated the material is nicely crystalline and exhibits adifferent pattern from the free base, as shown in FIG. 35. The DSC (FIG.36A) shows a small endotherm with an extrapolated onset of 180° C. whichwas followed by decomposition at approximately 225° C. The TGA (FIG.36B) shows a 0.5 wt % loss at about 105° C., suggesting the saltspecimen was relatively dry. The DVS isotherm is shown in FIGS. 37A and37B. This salt form only took up about 3 to 4 wt % water at highhumidity. The sample sorbed surface water until about 80% RH where rapiduptake began. The sample did not reach equilibrium at the highesthumidity. Hysteresis was observed between the sorption and desorptionsegments of the experiment. This sample did not appear deliquescent, butmay form a stable hydrate at high water activity levels. Additional workneeds to be done to understand the hydration profile of this salt form.The proton NMR spectrum (FIG. 38) confirmed the material was adinapsylate salt. The Raman spectrum of the dinapsylate salt sample isshown in FIG. 39. The dinapsylate salt was found to have a lowsolubility in water (0.2-0.4 mg/mL) relative to the free base.

Example 9. Preparation of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide Monoedisylate

The monoedisylate salt was prepared by using the same proceduredescribed in Example 3 except that sulfuric acid was replaced by1,2-ethanedisulfonic acid and the molar ratio of the free base to1,2-ethanedisulfonic acid is 1:1.

Alternatively, the free base as prepared in Example 2 was dissolved inmethanol, and a portion of this solution was transferred to provide 2 mgequivalent of free base. 1,2-Ethanedisulfonic acid was dissolved orsuspended in EtOH/Heptane or THF/Heptane. The free base and1,2-ethanedisulfonic acid solutions/suspensions (providing 1:1 molarratio of free base and 1,2-ethanedisulfonic acid) were mixed, and theresulting mixture solutions were dried under nitrogen purge at ambienttemperature to provide the desired monoedisylate salts as dry powderysolids.

XRD indicated the material is nicely crystalline and exhibits adifferent pattern from the free base, as shown in FIG. 40. The DSC (FIG.41A) shows a melting endotherm with an extrapolated onset of 317° C.which decomposes while melting. The TGA (FIG. 41B) shows a 0.5 wt % lossat about 105° C., suggesting the salt specimen was relatively dry. Hotstage microscopy data suggest the material was observed to melt anddecompose at about 315° C. The moisture sorption-desorption isotherm(FIGS. 42A and 42B) was collected using dynamic vapor sorption analysis.The monoedisylate salt did not show much water uptake up to 80% RH underthe experimental conditions, then it shows rapid sorption behavior up to85 wt % moisture at 90% RH. In the desorption phase, the monoedisylatesalt quickly dries by about 70% RH at which time it follows the sorptioncurve back to 0% RH. This isotherm indicate the material may form ahydrate at high humidity as well as deliquesce. The hydrate may only bestable at high humidities given the observation that the materialreadily dries by 70% RH on the desorption segment. The proton NMRspectrum (FIG. 43) confirmed the material was a mono edisylate salt.Raman spectrum of the monoedisylate salt sample is shown in FIG. 44. Themonoedisylate salt was found to have moderate solubility in water (≤14mg/mL).

Example 10. Preparation of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide Monooxalate

The monooxalate salt was prepared by using the same procedure describedin Example 3 except that sulfuric acid was replaced by gluconic acid andthe molar ratio of the free base to oxalic acid is 1:2.

Alternatively, the free base as prepared in Example 2 was dissolved inmethanol, and a portion of this solution was transferred to provide 2 mgequivalent of free base. Oxalic acid was dissolved or suspended inEtOH/Heptane or THF/Heptane. The free base and gluconic acidsolutions/suspensions (providing 1:2 molar ratio of free base andgluconic acid) were mixed, and the resulting mixture solutions weredried under nitrogen purge at ambient temperature to provide the desiredmonooxalate salts as dry powdery solids.

XRD indicated the material is crystalline and exhibits a differentpattern from the free base, as shown in FIG. 45. The DSC (FIG. 46A)shows a small but sharp endotherm with onset of 207° C. followed by asharp melting endotherm with an extrapolated onset of 233° C. The TGA(FIG. 46B) shows a 1.5 wt % loss at about 105° C., suggesting the saltspecimen was dry. The moisture sorption-desorption isotherm (FIGS. 47Aand 47B) was collected using dynamic vapor sorption analysis. Themonooxalate sample did not absorb much water over most of the scan. Thesample began taking up water more rapidly above 50% RH, but even at 95%RH the sample had only gained 1.5 wt % water. In the desorption phase,the salt showed little hysteresis, with the desorption curve being verysimilar to the sorption curve. Overall, the sorption characteristicsindicate this salt form did not take up much water. The proton NMR andRaman spectra of the monooxalate salt sample are shown in FIGS. 48 and49, respectively.

Example 11. Large Scale Preparation of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide (Free Base)

A 5 L flask was charged with LM11A31 diHCl salt (148 g, 0.468 mol) andDCM (3 L, 20 vol). A solution of aqueous sodium hydroxide (35.6 g, 0.889mol, 1.9 eq) in deionized water (148 mL, 1 vol) was slowly added to theheterogeneous mixture eventually forming a clear solution. The mixturewas transferred to a separatory funnel and the lower organic layer wasdrained. The upper aqueous layer was extracted with DCM (3×100 mL) andthe organic layers were combined and dried over sodium sulfate. Thesolution was concentrated to an oil which crystallized to a waxy whitesolid upon standing. The solids were dried under high vacuum to afford105 g (95% yield) of 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamideFree Base. ¹H NMR, LC-MS confirmed the identity and XRD pattern matchedthe small scale screen sample pattern.

Example 12. Large Scale Preparation of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide Disulfate

To a solution of 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide freebase (25 g, 0.103 mol) dissolved in absolute, anhydrous ethanol (250 mL,10 vol) cooled in an ice-water bath was slowly added concentratedsulfuric acid (4 mL, 75 mmol) by dropwise addition. Precipitationimmediately occurred causing stirring to stop. The ice-water bath wasremoved and the addition of ethanol (200 mL) and isopropanol (225 mL)was necessary to restart stirring. The remaining required sulfuric acid(7 mL, 131 mmol) was slowly added in an ethanol:isopropanol solution(2:1, 75 mL). An exotherm (20.8° C.-24.0° C.) was observed. The whiteslurry was allowed to stir overnight under positive nitrogen pressure.The mixture was then filtered washing with isopropanol (150 mL) anddried under high vacuum (35° C.-40° C.) to afford 33.6 g (75% yield) of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide Disulfate as a whitesolid. ¹H NMR, LC-MS confirmed the identity and XRD pattern matches thesmall scale screen sample pattern.

Example 13. Large Scale Preparation of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide Ditosylate

To a solution of 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide freebase (15 g, 0.062 mol) dissolved in anhydrous tetrahydrofuran (300 mL,20 vol) was added p-toluenesulfonic acid monohydrate (23.4 g, 0.123 mol,2 eq) in one portion. The initially clear mixture becomes cloudy andproduces a mild exotherm. After about 15 min, crystals begin toprecipitate from solution and the mixture continued to stir for 1.5 h.The solids were collected by vacuum filtration, and the wet cake wasdried in a 40° C. vacuum oven to afford 32.5 g (90% yield) of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide Ditosylate as a whitesolid. ¹H NMR confirmed the identity and XRD pattern matches the smallscale screen sample pattern.

Example 14. Large Scale Preparation of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide Dinapsylate

To a solution of 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide freebase (15 g, 0.062 mol) dissolved in anhydrous tetrahydrofuran (300 mL,20 vol) was added 2-naphthalene sulfonic acid hydrate (25.7 g, 0.123mol, 2 eq) in one portion. Solids rapidly precipitate from the initiallycloudy mixture. The mixture was stirred at ambient temperature for about30 min, and then the solids were collected by vacuum filtration. The wetcake was dried in a 40° C. vacuum oven to afford 33.9 g (83% yield) of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide Dinapsylate as awhite solid. ¹H NMR confirmed the identity and XRD pattern matches thesmall scale screen sample pattern.

Example 15. Large Scale Preparation of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide Monoedisylate

To a solution of 2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide freebase (20 g, 0.082 mol) dissolved in methanol (400 mL, 20 vol) was added1,2-ethanedisulfonic acid dihydrate (18.6 g, 0.082 mol, 1 eq) in oneportion. The homogeneous mixture quickly becomes cloudy, and after about5 min, solids precipitate. Agitation became difficult and an additional200 mL methanol was added to facilitate stirring. The mixture wasstirred at ambient temperature for about 30 min, and then the solidswere collected by vacuum filtration. The wet cake was dried in a 40° C.vacuum oven to afford 33.4 g (93% yield) of2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide edisylate as a whitesolid. ¹H NMR confirmed the identity and XRD pattern matches the smallscale screen sample pattern.

Example 16. Stability Study of Representative Salts

Four representative salts, i.e., monoedisylate, ditosylate, dinapsylateand disulfate, prepared at the 30 plus gram scale were challenged usingheat (solids stored at 25 and 60° C. for 1 week), oxidation (solidsstored in oxygen headspace at 25° C. for 1 week), light (UV source underICH confirmatory conditions>200 Whr/m²), and solutions (in HPLC diluent)at 25 and 40° C. for 1 week. Stressed samples were analyzed using HPLCto determine their impurity profiles.

TABLE 10 Summary of HPLC Stability Data on Representative Salts. HPLCTotal Area Normalization - Area % Purity Test Conditions of the SaltsFree Base Disulfate Ditosylate Dinapsylate Monoedisylate Solid State -Ambient 100 99.98 99.82 99.90 99.79 Solid State - 60 C. N/a 99.98 99.9499.87 99.95 Solution* - Ambient N/a 99.90 99.89 99.87 999.81 Solution* -40 C. 99.89 99.75 99.91 99.96 99.90 Oxidation Ambient 99.97 99.97 99.9299.81 99.95 Photo Stability - Dark Control 99.97 99.97 99.94 99.85 99.97Photo Stability - Exposed 99.98 99.94 99.93 99.82 99.86 *Solution ofwater and acetonitrile (1:1). **N/a = Data not available.

The stability results shown in Table 10 represent the averages of twoinjections of duplicate sample preparations. The HPLC stability datashowed that the salts exhibited little to no degradation with theconditions used.

To confirm the little or no degradation observed in the HPLC stabilitystudy, some samples (solids stored at 60° C. and oxidation) of four ofthe salts and free base were further analyzed by proton NMR (i.e.,HNMR). The analysis was qualitative.

FIGS. 50 to 54 showed the proton NMR overlay spectra for samplesanalyzed during the stability portion of the study. The NMR stabilitydata showed that the salts exhibited high stability with little or nodegradation under stress. The NMR stability data also showed that thesalts are slightly more stable than the free base. Specifically, slightdegradation of free base after heat stress can be seen in the NMRspectra.

Example 17. Pharmacokinetic Study of Representative Salts

The objective of this study was to provide preliminary pharmacokineticinformation regarding the exposure of different salt forms of LM11A-31in rat plasma and brain when dosed by oral gavage. Groups consisting ofnine male rats received single doses of 25 mg/kg free base by oralgavage. Plasma samples were obtained from three rats per timepoint afteradministration (0.5, 1, 2, 3, 4, and 8 hours) and brain samples werecollected at 1-, 3-, and 8-hour terminations (three rats per timepoint).

The samples were analyzed by LC-MS/MS to determine the plasma and brainconcentrations of the test article. Pharmacokinetic analysis of theplasma concentration data was conducted using noncompartmental analysiswith WinNonlin Version 4.1. Plasma pharmacokinetic parameters aresummarized in Table 11 and Table 12 below:

TABLE 11 Salt T_(1/2) T_(max) C_(max) AUC_(all) AUC_(INF) AUC_(%Extrap)(dosed) Rsq (h) (h) (ng/mL) (h * ng/mL) (h * ng/mL) (%) Free base 0.9871.05 0.5 371 321 316 4.81 Ditosylate 0.944 0.63 0.5 296 295 290 1.45Disulfate 1.000 1.10 0.5 413 416 410 5.26 Dinapsylate 0.890 1.90 0.5 335270 280 3.44 Edisylate 0.973 0.708 0.5 284 247 243 1.52

TABLE 12 Salt (dosed) Brain:Plasma Ratio Maximum Brain Level (ng/gtissue) Free base 2.0-3.5 105 Ditosylate 1.0-5.7 120 Disulfate 0.6-1.877 Dinapsylate 3.5-4.4 123 Edisylate 1.4-3.3 98

In general, the disulfate salt resulted in higher exposure (AUC andCmax) than the free base and the dinapsylate salt has a longer terminalplasma half-life and higher brain-to-plasma ratio than the free base.Overall the disulfate and dinapsylate salts demonstrate better PKproperties than the free base.

The patents and publications listed herein describe the general skill inthe art and are hereby incorporated by reference in their entireties forall purposes and to the same extent as if each was specifically andindividually indicated to be incorporated by reference. In the case ofany conflict between a cited reference and this specification, thespecification shall control. In describing embodiments of the presentapplication, specific terminology is employed for the sake of clarity.However, the invention is not intended to be limited to the specificterminology so selected. Nothing in this specification should beconsidered as limiting the scope of the present invention. All examplespresented are representative and non-limiting. The above-describedembodiments may be modified or varied, without departing from theinvention, as appreciated by those skilled in the art in light of theabove teachings. It is therefore to be understood that, within the scopeof the claims and their equivalents, the invention may be practicedotherwise than as specifically described.

The invention claimed is:
 1. A sulfuric acid addition salt of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide made by theprocess of contacting a solution of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide in a solventwith sulfuric acid in a mole ratio of about 0.75:1 or more of sulfuricacid to (2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide andseparating the sulfuric acid addition salt of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide formed fromsaid solvent, wherein said sulfuric acid addition salt exhibits an X-raypowder diffraction pattern under Cu—K-α radiation comprising peaks at21.784±0.5; 22.468±0.5, 19.277±0.5, 24.618±0.5 and 15.499±0.5 degreestwo-theta.
 2. The sulfuric addition salt of claim 1, wherein saidsulfuric acid addition salt of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide exhibits aRaman spectrum comprising peaks at 2980±10; 2943±10; 2889±10; and1033±10 cm⁻¹, optionally further comprising peaks at 975±10 and 851±10cm⁻¹.
 3. The sulfuric acid addition salt of claim 1, wherein the moleratio of sulfuric acid to(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide is about 2:1.4. The sulfuric acid addition salt of claim 1, wherein the solventcomprises an alcohol.
 5. The sulfuric acid addition salt of claim 1,wherein the solvent comprises ethanol.
 6. The sulfuric acid additionsalt of claim 1, wherein the solution of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide in saidsolvent is cooled prior to said contacting with sulfuric acid.
 7. Thesulfuric acid addition salt of claim 1, wherein said contactingcomprises dropwise addition of sulfuric acid to said solution of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide in thesolvent.
 8. The sulfuric acid addition salt of claim 1, wherein saidseparating the sulfuric acid addition salt of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide formed fromsaid solvent comprises filtering.
 9. A method of preparing a sulfuricacid addition salt of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide comprisingcontacting a solution of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide in a solventwith sulfuric acid in a mole ratio of about 0.75:1 or more of sulfuricacid to (2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide andseparating the sulfuric acid addition salt of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide formed fromsaid solvent, wherein said sulfuric acid addition salt exhibits an X-raypowder diffraction pattern under Cu—K-α radiation comprising peaks at21.784±0.5; 22.468±0.5, 19.277±0.5, 24.618±0.5 and 15.499±0.5 degreestwo-theta.
 10. The method of claim 9, wherein said sulfuric acidaddition salt of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide exhibits aRaman spectrum comprising peaks at 2980±10; 2943±10; 2889±10; and1033±10 cm⁻¹, optionally further comprising peaks at 975±10 and 851±10cm⁻¹.
 11. The method of claim 9, wherein the mole ratio of sulfuric acidto (2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide is about2:1.
 12. The method of claim 9, wherein the solvent comprises analcohol.
 13. The method of claim 9, wherein the solvent comprisesethanol.
 14. The method of claim 9, wherein the solution of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide in saidsolvent is cooled prior to said contacting with sulfuric acid.
 15. Themethod of claim 9, wherein said contacting comprises dropwise additionof sulfuric acid to said solution of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide in saidsolvent.
 16. The method of claim 9, wherein said separating the sulfuricacid addition salt of(2S,3S)-2-amino-3-methyl-N-(2-morpholinoethyl)-pentanamide formed fromsaid solvent comprises filtering.